Navigating the multifaceted intricacies of the Na+-Cl- cotransporter, a highly regulated key effector in the control of hydromineral homeostasis.

The Na+-Cl- cotransporter (NCC; SLC12A3) is a highly regulated integral membrane protein that is known to exist as three splice variants in primates. Its primary role in the kidney is to mediate the cosymport of Na+ and Cl- across the apical membrane of the distal convoluted tubule. Through this role and the involvement of other ion transport systems, NCC allows the systemic circulation to reclaim a fraction of the ultrafiltered Na+, K+, Cl-, and Mg+ loads in exchange for Ca2+ and [Formula: see text]. The physiological relevance of the Na+-Cl- cotransport mechanism in humans is illustrated by several abnormalities that result from NCC inactivation through the administration of thiazides or in the setting of hereditary disorders. The purpose of the present review is to discuss the molecular mechanisms and overall roles of Na+-Cl- cotransport as the main topics of interest. On reading the narrative proposed, one will realize that the knowledge gained in regard to these themes will continue to progress unrelentingly no matter how refined it has now become.

Inclusion of water temperature in a fuzzy logic Atlantic salmon (Salmo salar) parr habitat model.

As water temperature is projected to increase in the next decades and its rise is clearly identified as a threat for cold water fish species, it is necessary to adapt and optimize the tools allowing to assess the quantity and quality of habitats with the inclusion of temperature. In this paper, a fuzzy logic habitat model was improved by adding water temperature as a key determinant of juvenile Atlantic salmon parr habitat quality. First, salmon experts were consulted to gather their knowledge of salmon parr habitat, then the model was validated with juvenile salmon electrofishing data collected on the Sainte-Marguerite, Matapedia and Petite-Cascapedia rivers (Québec, Canada). The model indicates that when thermal contrasts exist at a site, cooler temperature offered better quality of habitat. Our field data show that when offered the choice, salmon parr significantly preferred to avoid both cold areas (<15 °C) and warm areas (>20.5 °C). Because such thermal contrasts were not consistently present among the sites sampled, the model was only validated for less than 60% of the sites. The results nevertheless indicate a significant correlation between median Habitat Quality Index and parr density for the Sainte-Marguerite River (R2 = 0.38). A less important, albeit significant (F-test; p = 0.036) relationship was observed for the Petite-Cascapedia river (R2 = 0.14). In all instances, the four-variable (depth, velocity, substrate size and temperature) model provided a better explanation of parr density than a similar model excluding water temperature.

Tissue-specific profiling reveals modulation of cellular and mitochondrial oxidative stress in normal- and low-birthweight piglets throughout the peri-weaning period.

Weaning is known to induce important nutritional and energetic stress in piglets. Low-birthweight (LBW) piglets, now frequently observed in swine production, are more likely to be affected. The weaning period is also associated with dysfunctional immune responses, uncontrolled inflammation and oxidative stress conditions that are recognized risk factors for infections and diseases. Mounting evidence indicates that mitochondria, the main cellular sources of energy in the form of adenosine 5' triphosphate (ATP) and primary sites of reactive oxygen species production, are related to immunity, inflammation and bacterial pathogenesis. However, no information is currently available regarding the link between mitochondrial energy production and oxidative stress in weaned piglets. The objective of this study was to characterize markers of cellular and mitochondrial energy metabolism and oxidative status in both normal-birthweight (NBW) and LBW piglets throughout the peri-weaning period. To conduct the study, 30 multiparous sows were inseminated and litters were standardized to 12 piglets. All the piglets were weighted at day 1 and 120 piglets were selected and assigned to 1 of 2 experimental groups: NBW (n = 60, mean weight of 1.73 ± 0.01 kg) and LBW piglets weighing less than 1.2 kg (n = 60, 1.01 ± 0.01 kg). Then, 10 piglets from each group were selected at 14, 21 (weaning), 23, 25, 29 and 35 days of age to collect plasma and organ (liver, intestine and kidney) samples. Analysis revealed that ATP concentrations were lower in liver of piglets after weaning than during lactation (P < 0.05) thus suggesting a significant impact of weaning stress on mitochondrial energy production. Oxidative damage to DNA (8-hydroxy-2'-deoxyguanosine, 8-OHdG) and proteins (carbonyls) measured in plasma increased after weaning and this coincides with a rise in enzymatic antioxidant activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) (P < 0.05). Mitochondrial activities of both GPx and SOD are also significantly higher (P < 0.05) in kidney of piglets after weaning. Additionally, oxidative damage to macromolecules is more important in LBW piglets as measured concentrations of 8-OHdG and protein carbonyls are significantly higher (P < 0.05) in plasma and liver samples, respectively, than for NBW piglets. These results provide novel information about the nature, intensity and duration of weaning stress by revealing that weaning induces mitochondrial dysfunction and cellular oxidative stress conditions which last for at least 2 weeks and more severely impact smaller piglets.

Development of a flatbed passive integrated transponder antenna grid for continuous monitoring of fishes in natural streams.

This paper describes a flatbed antenna grid designed for continuous remote monitoring of fish tagged with 23 mm passive integrated transponder (PIT) tags in a natural stream with extensive spatial coverage. A range of applications of the system is presented.

Kinetics of plasma apolipoprotein C-III as a determinant of diet-induced changes in plasma triglyceride levels.

OBJECTIVE: To compare the effect of a high monounsaturated fatty acid (MUFA) diet and of a control low-fat diet consumed under ad libitum conditions on plasma apolipoprotein (apo) C-III metabolism. DESIGN: Randomized, two-arm parallel dietary trial. SETTING: Diets were prepared and consumed at the metabolic kitchen of the Department of Food Sciences and Nutrition, and laboratory analyses were performed at the Institute of Nutraceuticals and Functional Foods at Laval University. SUBJECTS AND INTERVENTIONS: Eighteen men were randomly assigned to either the high MUFA diet or the low-fat control diet, which they consumed for 6-7 weeks. Before and after the dietary intervention, subjects received a primed-constant infusion of [5,5,5-D(3)]-L-leucine for 12 h under constant feeding conditions for the determination of plasma apoC-III kinetics. RESULTS: The high-MUFA diet and the low-fat control diet had no significant impact on plasma apoC-III production rate (PR) or fractional catabolic rate. However, diet-induced variations in plasma apoCIII PR predicted the reduction in plasma triglycerides and apoC-III levels (r=0.85, P<0.01 and r=0.73, P<0.05, respectively) in the high MUFA group only. CONCLUSIONS: These results suggest that the hypotriglyceridemic effect of a high-MUFA diet may be attributable in part to a reduced hepatic production of apoC-III. SPONSORSHIP: This study was supported in part by an operating grant from the Canadian Institutes of Health Research (CIHR), and the Canada Research Chair in Nutrition and Cardiovascular Health (B Lamarche).

Prolonged postprandial responses of lipids and apolipoproteins in triglyceride-rich lipoproteins of individuals expressing an apolipoprotein epsilon 4 allele.

The postprandial responses of apo B48, B100, E and lipids in triglyceride-rich lipoproteins (TRL) to a meal containing one-third of daily energy (39% fat calories) were compared in normolipidemic young men with apo E3/3 and apo E4/3 phenotypes. After the two groups consumed a diet rich in polyunsaturated fat for 15-29 d, their postabsorptive concentrations of TRL triglycerides, apo B48, and apo B100 were virtually identical, but their postprandial responses differed. In both groups, TRL apo B48 increased at 3 h but returned to postabsorptive values at 6 h only in the apo E3/3 group; in the apo E4/3 group the concentration of apo B48 at 6 h was 80% higher than postabsorptive values. TRL apo B100 also increased at 3 h in the two groups and fell to post-absorptive values at 6 h in the apo E3/3 group but remained 51% higher than postabsorptive concentrations in the apo E4/3 group; this response was closely coupled to that of TRL cholesterol and apo E. These observations suggest that clearance of intestinal and hepatogenous TRL remnants is impaired in young men with an apo E4/3 phenotype.

CCAAT/enhancer binding protein beta protects muscle satellite cells from apoptosis after injury and in cancer cachexia.

CCAAT/enhancer binding protein beta (C/EBPß), a transcription factor expressed in muscle satellite cells (SCs), inhibits the myogenic program and is downregulated early in differentiation. In a conditional null model in which C/EBPß expression is knocked down in paired box protein 7+ (Pax7+) SCs, cardiotoxin (CTX) injury is poorly repaired, although muscle regeneration is efficient in control littermates. While myoblasts lacking C/EBPß can differentiate efficiently in culture, after CTX injury poor regeneration was attributed to a smaller than normal Pax7+ population, which was not due to a failure of SCs to proliferate. Rather, the percentage of apoptotic SCs was increased in muscle lacking C/EBPß. Given that an injury induced by BaCl2 is repaired with greater efficiency than controls in the absence of C/EBPß, we investigated the inflammatory response following BaCl2 and CTX injury and found that the levels of interleukin-1ß (IL-1ß), a proinflammatory cytokine, were robustly elevated following CTX injury and could induce C/EBPß expression in myoblasts. High levels of C/EBPß expression in myoblasts correlated with resistance to apoptotic stimuli, while its loss increased sensitivity to thapsigargin-induced cell death. Using cancer cachexia as a model for chronic inflammation, we found that C/EBPß expression was increased in SCs and myoblasts of tumor-bearing cachectic animals. Further, in cachectic conditional knockout animals lacking C/EBPß in Pax7+ cells, the SC compartment was reduced because of increased apoptosis, and regeneration was impaired. Our findings indicate that the stimulation of C/EBPß expression by IL-1ß following muscle injury and in cancer cachexia acts to promote SC survival, and is therefore a protective mechanism for SCs and myoblasts in the face of inflammation.

Postprandial triglyceride response in visceral obesity in men.

Although metabolic disturbances are often observed in obese patients, increased accumulation of visceral adipose tissue (AT) has been shown to be more closely associated with high fasting triglyceride (TG) and insulin levels as well as with low HDL cholesterol concentrations than with excess body fatness per se. Interestingly, the fasting concentration of plasma TGs has been shown to be an important determinant of the magnitude and duration of the postprandial TG response. Yet little is known about the respective contributions of obesity versus excess visceral AT to the variation in postprandial TG clearance. In the present study, we examined potential differences in postprandial triglyceride-rich lipoprotein (TRL) responses in subjects characterized by high versus low levels of visceral AT. In a sample of 43 men (mean age: 41.3 +/- 9.6 years), we found that both excess body fat and visceral obesity were associated with increased postprandial TG responses in total TRL (r = 0.33-0.45). We also found a strong relationship between fasting plasma TG levels and postprandial total TRL-TG concentrations (r = 0.79, P < 0.0001). When matched for total body fat mass, individuals with high levels of visceral AT (> or =130 cm2; n = 10) as assessed by computed tomography were characterized by increased medium- and small-TRL-TG responses (P < 0.05) compared with subjects with low visceral AT accumulation (<130 cm2; n = 10). Moreover, this elevated response of small-TRL triglycerides noted in men with high levels of visceral AT was not accompanied by a concomitant increased retinyl palmitate response in this TRL fraction, suggesting that visceral obesity in men is accompanied by higher postprandial VLDL production than is found in obese men with lower levels of visceral AT. Increased postprandial insulin and free fatty acid (FFA) responses were also noted in men with high levels of visceral AT. Finally, postheparin plasma lipoprotein lipase activity was negatively correlated with the total-TRL-TG response in a subsample of 32 individuals (r = -0.37, P < 0.05). The results of the present study suggest that visceral obesity is associated with an impaired postprandial TG clearance. Furthermore, the exaggerated postprandial FFA response observed in subjects with high visceral AT suggests that visceral obesity may contribute to fasting and postprandial hypertriglyceridemia by altering FFA metabolism in the postprandial state.

Metabolic heterogeneity underlying postprandial lipemia among men with low fasting high density lipoprotein cholesterol concentrations.

The high triglyceride (TG) and low high density lipoprotein (HDL) cholesterol dyslipidemia has been associated with increased postprandial lipemia. Although fasting TG is a powerful predictor of postprandial hyperlipidemia, the role of hypoalphalipoproteinemia in postprandial TG metabolism is uncertain. We have studied postprandial lipemia among 63 men with low fasting plasma HDL cholesterol concentrations (<0.9 mmol/L), but with either low (<2.0 mmol/L) or high (>2.0 mmol/L) fasting plasma TG levels. A significant relationship was noted between postprandial TG response and fasting HDL cholesterol concentration (r = -0.43; P: < 0.0005). We also found that men with high TG/low HDL dyslipidemia (high TG and low HDL cholesterol; n = 16) were characterized by abdominal obesity as well as increased visceral adipose tissue accumulation, whereas normolipidemic controls (low TG and high HDL cholesterol; n = 26) and men with isolated low HDL cholesterol concentrations (low TG and low HDL cholesterol; n = 17) were not characterized by features of the insulin resistance syndrome (visceral obesity, hyperinsulinemia, and hypertriglyceridemia). Although controls and men with isolated low HDL cholesterol levels had similar postprandial lipemic responses, men with the high TG/low HDL dyslipidemia had a marked increase in their postprandial TG responses to the fat load compared with the other subgroups (P: < 0. 001). Men with the high TG/low HDL dyslipidemia were also characterized by higher concentrations of apolipoprotein (apo) B-48 and B-100 particles (chylomicron remnants and very low density lipoproteins, respectively) before and during the postprandial period compared with the other subjects. These results suggest that low HDL cholesterol concentration is a heterogeneous metabolic phenotype that it is not associated with postprandial hyperlipidemia unless accompanied by other features of the insulin resistance syndrome.

Influence of fish protein as compared to casein and soy protein on serum and liver lipids, and serum lipoprotein cholesterol levels in the rabbit.

Serum and hepatic cholesterol and triglyceride levels, and serum lipoprotein cholesterol were investigated in rabbits fed fish protein as compared to casein and soy protein as part of a 20% protein, low fat, cholesterol-free, semi-purified diet. A nonpurified diet was used as a control. After a 28-day experimental period, rabbits fed casein developed hypercholesterolemia compared to those fed the soy protein diet. Serum cholesterol levels of rabbits fed fish protein was intermediate and not different from that of the casein or the soy protein group. However, serum triglycerides were higher in the fish group than in the casein group. Feeding of fish protein resulted in a reduction of hepatic cholesterol compared to casein, indicating no direct relationship between serum and hepatic cholesterol. In addition, fish protein induced a decrease of cholesterol in the low density lipoproteins (LDL) compared to casein and an increase of cholesterol in the high density lipoproteins (HDL) compared to casein and soy protein. Reduction in LDL-cholesterol (LDL-C) and elevation in HDL-cholesterol (HDL-C) caused a 10-fold decrease in the LDL-C/HDL-C ratio of fish protein fed rabbits compared to those fed casein. This ratio was similar to that observed with soy protein which was also lower than the ratio of the casein group. Thus, since the LDL-C/HDL-C ratio has been shown to be a good indicator of the atherosclerosis risk, these results suggest that fish protein, as well as soy protein, may reduce the risk of atherosclerosis in rabbits, compared to casein.

The small, dense LDL phenotype as a correlate of postprandial lipemia in men.

The atherogenic dyslipidemia of the insulin resistance syndrome is characterized by hypertriglyceridemia (hyperTG), elevated apolipoprotein (apo) B levels, reduced high-density lipoprotein (HDL) cholesterol concentrations and by an increased proportion of small, dense low-density lipoprotein (LDL) particles. Although the hyperTG-low HDL cholesterol dyslipidemia has been associated with an impaired clearance of dietary fat, the contribution of the small, dense LDL phenotype as an independent predictor of postprandial triglyceride (TG) clearance remains uncertain. We have therefore compared the postprandial TG response among three subgroups of men characterized by small, intermediate or large LDL particles in a total sample of 69 men (mean age +/- SD; 45.1 +/- 10.5 years). To identify men with small versus large LDL particles, the first (LDL peak particle diameter < 251.9 A) and the third (> 257.6 A) tertiles of the distribution of LDL particle diameters were used as cutoff points. Men with small, dense LDL particles had the expected fasting dyslipidemic profile (high TG-low HDL cholesterol levels) compared to men with large, buoyant LDL particles. The oral lipid tolerance test revealed that men with small, dense LDL particles had significantly higher total-, large-, and medium-TG-rich lipoprotein (TRL) responses to a fatty meal than men with large LDL particles (P < 0.03). In addition, within a subgroup of normolipidemic men (TG < 2.3 mmol/l and HDL cholesterol > 0.9 mmol/l), those with small, dense LDL particles had higher levels of total-, medium- and small-TRL responses compared to men with large, buoyant LDL particles (P < 0.05). Moreover, normotriglyceridemic men with small, dense LDL had higher levels of small-TRLs measured 8 h after the ingestion of the fat meal (P < 0.05) compared to normolipidemic men with large, buoyant LDL particles. Results of the present study suggest that the dense LDL phenotype may be an additional fasting marker of an exaggerated postprandial TG response and of an impaired clearance of TRLs.

Intensive Care Delirium Screening Checklist: evaluation of a new screening tool.

OBJECTIVE: Delirium in the intensive care unit is poorly defined. Clinical evaluation is difficult in the setting of unstable, often intubated patients. A screening tool may improve the detection of delirium. METHOD: We created a screening checklist of eight items based on DSM criteria and features of delirium: altered level of consciousness, inattention, disorientation, hallucination or delusion, psychomotor agitation or retardation, inappropriate mood or speech, sleep/wake cycle disturbance, and symptom fluctuation. During 3 months, all patients admitted to a busy medical/surgical intensive care unit were evaluated, and the scale score was compared to a psychiatric evaluation. RESULTS: In 93 patients studied, 15 developed delirium. Fourteen (93%) of them had a score of 4 points or more. This score was also present in 15 (19%) of patients without delirium, 14 of whom had a known psychiatric illness, dementia, a structural neurological abnormality or encephalopathy. A ROC analysis was used to determine the sensitivity and specificity of the screening tool. The area under the ROC curve is 0.9017. Predicted sensitivity is 99% and specificity is 64%. CONCLUSION: This study suggests that the Intensive Care Delirium Screening Checklist can easily be applied by a clinician or a nurse in a busy critical care setting to screen all patients even when communication is compromised. The tool can be utilized quickly and helps to identify delirious patients. Earlier diagnosis may lead to earlier intervention and better patient care.

Delirium in an intensive care unit: a study of risk factors.

OBJECTIVES: (1) To establish risk factors for the development of delirium in an intensive care unit (ICU) and (2) to determine the effect of delirium on morbidity, mortality and length of stay. DESIGN: Prospective study. SETTING: Sixteen-bed medical/surgical ICU in a university hospital. PATIENTS: Two hundred and sixteen consecutive patients admitted to the ICU for more than 24 h during 5 months were included in the study. INTERVENTIONS: Medical history, selected laboratory values, drugs received and factors that may influence patient psychological and emotional well-being were noted. All patients were screened with a delirium scale. A psychiatrist confirmed the diagnosis of delirium. Major complications such as self-extubation and removal of catheters, as well as mortality and length of stay were recorded. RESULTS: Forty patients (19%) developed delirium; of these, one-third were not agitated. In the multivariate analysis hypertension, smoking history, abnormal bilirubin level, epidural use and morphine were statistically significantly associated with delirium. Traditional factors associated with the development of delirium on general ward patients were not significant in our study. Morbidity (self-extubation and removal of catheters), but not mortality, was clearly increased. CONCLUSION: Predictive risk factors for the development of delirium in studies outside the ICU may not be applicable to critically ill patients. Delirium is associated with increased morbidity. Awareness of patients at risk may lead to better recognition and earlier intervention.

Factorial experiment to determine influence of fish protein and fish oil on serum and liver lipids in rabbits.

Rabbits were fed purified diets consisting of casein (CA), fish protein (FP), and soy protein (SP) combined with MaxEpa oil (ME) or corn oil (CN) to determine the effects of dietary protein and lipid sources on serum total, lipoprotein, and hepatic lipid levels. Dietary proteins and lipids exerted significant (p < 0.05) separate effects on serum total cholesterol (TC) (p < 0.005), very-low-density lipoprotein cholesterol (VLDL-C) (p < 0.001), and high-density lipoprotein cholesterol (HDL-C) (p < 0.001), whereas only dietary proteins significantly affected low-density lipoprotein cholesterol (LDL-C) (p < 0.001) and the LDL-C/HDL-C ratio (p < 0.05). Hence, FP induced serum TC (233 mg/dl), VLDL-C (22 mg/dl), and LDL-C (151 mg/dl) intermediary to hypercholesterolemic CA (TC, 319 mg/dl; VLDL-C, 57 mg/dl; LDL-C, 204 mg/dl) and cholesterol-lowering SP (TC, 129 mg/dl; VLDL-C 19 mg/dl; LDL-C, 84 mg/dl). The twofold rise in HDL-C on feeding FP (35 mg/dl), compared with CA (20 mg/dl) and SP (16 mg/dl), resulted in a drop in LDL-C/HDL-C to a level similar to that of SP groups. The cholesterol-lowering action of ME (188 mg/dl), in contrast to CN (266 mg/dl), was reflected mainly in VLDL (ME, 15 mg/dl; CN, 50 mg/dl) but also in HDL (ME, 16 mg/dl; CN, 31 mg/dl) fractions. Compared with CN, the significant (p < 0.05) ME-induced rise in serum and VLDL triglycerides was accompanied by a significant (p < 0.001) drop in lipoprotein lipase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in the consumption of ethanol and flavored solutions in three strains of rats.

Several studies have shown a correlation between ethanol consumption and the intake of flavored solutions in rats, particularly sweet solutions. This observation, however, has not been shown in all strains of rats. The present study examined whether the intake of ethanol and that of flavored solutions would be related in Lewis (LEW), Wistar (WIS), and Wistar Kyoto (WKY) rats. During phase I, all rats were presented with water and a flavored solution following a continuous access paradigm as developed by Overstreet et al.: quinine (0.25% wt/vol), saccharin (0.1% wt/vol), ethanol (ETOH) (10% vol/vol), and saccharin-quinine (SQ) solutions (0.4% wt/vol-0.04% wt/vol). During phase II, fluid presentations were reduced to a 10-min limited access schedule and were presented in the same order. Results showed strain differences in intake and preference for ETOH and SQ during both phases, but not in quinine or saccharin intake. ETOH and saccharin intake were only correlated in the LEW strain during limited access drinking, while ETOH and SQ intake were correlated in the LEW strain as well as when all strains were collapsed during continuous drinking. These findings suggested that any association between ETOH and sweet intake may not be generalizable to all rat strains. The animals used in this study may have differed in taste sensitivity, as low ETOH-consuming LEW rats were sensitive to the bitter taste of quinine alone, as well as when mixed with saccharin. Sensitivity to bitter tastes may be an important predictor of low ETOH consumption and/or preference. These data provide further evidence for the role of taste factors in the mediation of voluntary ETOH consumption in rats.

Role of dietary fish protein in the regulation of plasma lipids.

The following studies have been carried out to compare the effects of fish protein with other dietary proteins on plasma cholesterol and lipoproteins in animal models and in humans. In rabbits, fish protein has been shown to induce relatively variable effects compared to casein and soy protein on serum cholesterol depending in part on the origin of dietary lipids with which it is combined. In a protein-lipid interaction study, casein, soy or cod protein were combined with corn or coconut oil. Casein and soy protein in the presence of corn oil induced lower serum cholesterol levels despite its combination with either corn or coconut oil. This is in part due to serum high density lipoprotein (HDL) cholesterol concentrations, which were consistently higher with cod protein than with either casein or soy protein, regardless of the dietary lipid source. In rabbits, this rise in HDL cholesterol was associated with a decrease in very low density lipoprotein (VLDL) triglycerides and an increase in postheparin plasma lipoprotein lipase activity. The effects of lean white fish on plasma lipoproteins also have been investigated in post and premenopausal women fed a low-fat, high P/S (polyunsaturated/saturated fat) ratio diet. In postmenopausal women, lean white fish compared with other animal protein products induced higher concentrations of plasma cholesterol, LDL-apolipoprotein (apo) B and HDL cholesterol, mainly in the HDL3 fraction. In premenopausal women, lean white fish induced lower concentrations of VLDL triglycerides and higher concentrations of LDL-apoB in plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction between dietary proteins and lipids in the regulation of serum and liver lipids in the rabbit. Effect of fish protein.

Purified diets varying in dietary protein, namely casein (CA), soy protein (SP), fish protein (FP), and lipid origin (corn oil (CN), coconut oil (CO)) were fed to rabbits to evaluate the effects of protein and fat source, as well as protein-lipid interactions, on serum total, lipoprotein and hepatic lipid levels. Dietary proteins and lipids exerted a separate effect on serum total cholesterol (C), very low-density lipoprotein cholesterol (VLDL-C), and low-density lipoprotein cholesterol to high density lipoprotein cholesterol (LDL-C/HDL-C) ratio. Hence, CA increased serum cholesterol compared to SP, while coconut oil enhanced serum and VLDL-C, and decreased LDL-C/HDL-C compared to corn oil. Dietary proteins interacted with dietary lipids to modulate HDL-C levels. Thus, FP maintained a high level of HDL-C regardless of lipid origin, compared to CA and SP whose HDL-C levels were decreased by corn oil, compared to coconut oil. A dietary protein-lipid interaction was also observed in the regulation of liver cholesterol levels. Coconut oil, compared to corn oil, decreased liver cholesterol in rabbits fed FP, whereas hepatic cholesterol concentration was unaltered by dietary lipid source in CA- and SP-fed rabbits. These results demonstrate that dietary proteins act synergistically with dietary lipids to regulate cholesterol metabolism in the rabbit.

Rare detection of Neospora caninum in placentas from seropositive dams giving birth to full-term calves.

Neospora caninum is thought to be transmitted to cattle by dogs, the only known definitive host. Although aborted fetuses seem the most likely source of infective material for dogs, placentas from seropositive dams appear also as a potential source of infective material. The objective of the study was to evaluate the presence of N. caninum organisms in placentas of full-term calves born to seropositive cows. Sixteen placentas, 11 from Neospora-seropositive cows, were examined histologically and by immunohistochemistry and polymerase chain reaction (PCR) assay for the presence of N. caninum. Mild placentitis was observed in all placentas. Neospora caninum was not identified by immunohistochemistry, but placentas from 2 seropositive dams were positive for N. caninum by PCR. These results suggest that placentas of full-term calves from seropositive cows may be a potential source of N. caninum for dogs, but the incidence of this mode of transmission is likely to be low.

Failure of dogs to shed oocysts after being fed bovine fetuses naturally infected by Neospora caninum.

Neospora caninum is a protozoan that causes abortion in cattle. The dog has recently been identified as a definitive host for N. caninum. To verify if bovine fetuses can infect dogs, nine 2-4-month-old dogs were fed bovine fetuses naturally infected by N. caninum. None of the dogs excreted oocysts, seroconverted, had clinical signs or lesions compatible with N. caninum infection. Additional studies will be necessary to determine the natural mode of infection of dogs by N. caninum.

Vertical and horizontal transmission of Neospora caninum in dairy herds in Québec.

Neospora caninum is an important cause of abortion in dairy cattle. The objective of this observational study was to estimate the rate of vertical transmission of N. caninum in dairy herds in Québec and to investigate horizontal transmission in the same herds. The genealogy of cows from 23 dairy herds were examined. Prevalence of seropositive animals in herds studied varied from 4.3% to 61.8% (average, 21.9%). The overall rate of vertical transmission was estimated to be 44.4%, varying from 0% to 85.7%. Seven cases of horizontal transmission were identified in 6 of the 23 herds studied. Estimated vertical transmission rate varied from herd to herd, but appeared to be higher in herds with a high prevalence of seropositive animals. Although horizontal transmission was identified in 6 herds, it does not appear to be the major route of infection for N. caninum.