| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
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| Analytical performance and clinical utility of a direct LDL-cholesterol assay in a hyperlipidemic pediatric population Harris, N., E. J. Neufeld, et al. (1996), Clin Chem 42(8 Pt 1): 1182-8. Abstract: This study compares a new latex immunoseparation method for the direct determination of plasma low-density lipoprotein cholesterol (LDL-C) with the reference procedure for LDL-C (beta-quantification) in a pediatric hyperlipidemic population. The direct LDL-C assay has a mean bias of -98 mg/L in a fasting group (n = 96) of patients (mean triglycerides 1057 +/- 720 mg/L) and a bias of +177 mg/L in a nonfasting group (n = 42, mean triglycerides 4854 +/- 5457 mg/L). The mean total analytical error calculated from our data is 13.8%. The direct LDL-C assay and the commonly used Friedewald calculation respectively classified 81% and 84% of fasting patients correctly, according to the cutoffs of 1100 and 1300 mg/L for LDL-C set by the National Cholesterol Education Program for pediatric patients. Of combined fasting and nonfasting patients, 80% were correctly classified by the direct LDL-C assay. Therefore, despite several analytical shortcomings, the direct LDL-C assay may be useful in managing hyperlipidemic children without the need for a fasting specimen. |
| Analytical performance of a direct assay for LDL-cholesterol Smets, E. M., N. C. Pequeriaux, et al. (2001), Clin Chem Lab Med 39(3): 270-80. Abstract: We evaluated a direct assay for the determination of LDL-cholesterol (LDL-C) L-Type assay, Wako Pure Chemicals in two laboratories. This assay is applicable to most random access clinical chemistry analyzers, allowing full automation. Between-run coefficient of variation (NCCLS EP5) varied between 1.29% and 3.13% and thus met the National Cholesterol Education Program (NCEP) goal. The assay was considered linear over a physiologically relevant range of LDL-C, 2.22 to 7.04 mmol/l (NCCLS EP6). Method comparison yielded identical results at both evaluation sites for LDL-C when assayed with the direct method. LDL-C results obtained with the homogeneous method under investigation (y) differed significantly from values from density-gradient ultracentrifugation (x) according to Chung (y = 0.87x + 0.43 mmol/l, s(yx) = 0.38 mmol/l, r = 0.91). With the latter method as a reference method, mean bias was 3.16% meeting the NCEP criteria. Diagnostic performance was excellent at a clinically relevant cut-off level of 3.37 mmol/l. Results of the direct method (y) and the commonly used Friedewald formula (x) were highly correlated (s(yx) = 0.22 mmol/l, r = 0.97), but both slope and intercept differed significantly from one and zero respectively (y = 0.90x + 0.37 mmol/l). Bilirubin, hemolysis and ascorbate did not interfere; triglycerides did not cause clinically relevant interference below 11.3 mmol/l. The direct method we investigated is user-friendly and provides an improvement in the determination of LDL-C in routine laboratories. |
| Analytical performance of a direct assay for LDL-cholesterol: a comparative assessment versus Friedewald's formula Turkalp, I., Z. Cil, et al. (2005), Anadolu Kardiyol Derg 5(1): 13-7. Abstract: OBJECTIVE: Because low density lipoprotein-cholesterol (LDL-C) is a modifiable risk factor for coronary artery disease (CAD), its routine measurement is recommended in the evaluation and management of hypercholesterolemia. Concentrations of LDL-C are commonly monitored by means of the Friedewald formula (FF), which provides a relative estimation of LDL-C concentration when the triglyceride (TGs) concentration is <200 mg/dl and there are no abnormal lipids. Because of the limitations of the Friedewald calculation, direct methods for an accurate quantification of LDL-C are needed. METHODS: We critically examined an immunoseparation method for direct assay of LDL-C in a comparison with FF. 1) We measured intraassay and interassay precision using quality-control sera and patient serum pools. Accuracy was evaluated from total error analyses. Sample stability was examined over 2 months. 2) The LDL-C levels obtained with direct assay were compared with those calculated by the FF in 47 randomly chosen patient samples. The samples were classified as group 1 (patients with TGs 60-308 mg/dl, n=25) and group 2 (patients with TGs 320-695 mg/dl, n=22). RESULTS: The direct immunoseparation assay displayed an excellent precision (total coefficient of variance (CV)<2.5%, intraassay CV<1.5% and interassay CV<1.5%). Mean total error was 4.34%. The direct assay met the current National Cholesterol Education Program (NCEP) requirements for LDL-C testing for precision and accuracy. The results of direct method (x) and the FF (y) were highly correlated (r=0.9908, y=1.030 x -0.289, n=25) in group 1, but the results of two methods disagreed (r=0.716, y=0.956 x -24.869, n=22) in group 2 (patients with TGs 320-695 mg/dl). CONCLUSION: The direct immunoseparation assay meets the currently established analytical performance goals and may be useful for the diagnosis and management of hyperlipidemic patients. |
| Analytical performance of the Genzyme LipoPro Lp(a) kit for plasma lipoprotein(a)-cholesterol assay Gaw, A., E. A. Brown, et al. (2000), Br J Biomed Sci 57(1): 13-8. Abstract: The analytical performance of a new assay for plasma lipoprotein(a)-cholesterol (Lpa-C) was compared with that of our existing Lp(a) protein assay. The Lp(a)-C assay utilises lectin affinity chromatography to isolate intact Lp(a) particles. The effect of apo(a) isoform size on this system was assessed and found to be negligible. Plasma Lp(a) concentrations measured by both assays were in excellent accord in 24 subjects with Lp(a) protein concentrations ranging from 1-65 mg/dL (r2 = 0.916). Linearity of the Lp(a)-C assay system was excellent (r2 = 0.997) and within-run precision was 6.9% at an Lp(a)-C concentration of 0.3 mmol/L. Between-calibration precision was checked and proved to be 7.9%. The lectin-binding reagent used in the assay bound different sized apo(a) isoforms equally, and the recovery of Lp(a) from the reagent was, on average, 64%. We conclude that the Lp(a)-C assay system performs well but that further information is required on what new information, if any, the assay provides over traditional Lp(a) protein measurements by enzyme-linked immunosorbent assay (ELISA) or immunoturbidimetry. |
| Analytical quality of near-patient blood cholesterol and glucose determinations du Plessis, M., J. B. Ubbink, et al. (2000), Clin Chem 46(8 Pt 1): 1085-90. Abstract: BACKGROUND: Screening for diabetes and hypercholesterolemia is widely advocated, and extra-laboratory testing could play a major role in cost-effective population screening. We wished to assess the analytical quality and interchangeability of capillary blood cholesterol and glucose assays as performed on near-patient devices in pharmacies in Pretoria, South Africa. METHODS: Accuracy of near-patient and laboratory analyzers was assessed by analyses of human-serum-based reference material. To assess interchangeability in routine use, six volunteers visited each of 12 randomly selected pharmacies consecutively during a 3-week period to have their fasting blood glucose and cholesterol concentrations determined. For comparison purposes, a similar procedure was followed to evaluate the eight clinical chemistry laboratories servicing Pretoria and surroundings. RESULTS: The analytical performances in our laboratory of a single point-of-care instrument and of a laboratory analyzer compared well. Nevertheless, between-pharmacy analytical variation was larger than between-laboratory variation (11% vs 6.1% for cholesterol; 10% vs 7.6% for glucose). For glucose measurements, near-patient testing in pharmacies demonstrated a bias of -48.1% to 16.2%, whereas bias for laboratory measurements was -1.0% to 7.4%. Cholesterol assays showed a bias of -5.6% to 16.6% in pharmacies compared with -10.6% to 3.7% in laboratories. The percentage of closeness to the homeostatic set point for a single glucose and cholesterol determination done in any pharmacy was 24.6% and 23.6%, respectively. The corresponding values for laboratories were 16.9% and 15.6%, respectively. CONCLUSIONS: Although modern point-of-care instruments allow high-quality blood analyses under ideal conditions, performance goals often are not achieved in practice as indicated by a higher uncertainty of cholesterol and glucose blood results when determined in pharmacies. Nonuniformity of calibration procedures, deficiencies in training, a lack of internal quality control, and the absence of an external quality assessment program may all contribute to the current state of affairs. |
| Analytical reviews in clinical biochemistry: the quantitative analysis of cholesterol Richmond, W. (1992), Ann Clin Biochem 29 (Pt 6): 577-97. |
| Anatomical heterogeneity of the intestinal mucosa and cholesterol homeostasis. A review of studies with normal and genetically hypercholesterolemic (RICO) Rat Lutton, C. (1996), Digestion 57(1): 1-10. Abstract: Quantitative data on cholesterol movements in mucosa cell as a function of its localization in the small intestine have been obtained in normocholesterolemic (SW) or genetically hypercholesterolemic (RICO) rats. Bile cholesterol absorption is greater and more proximal than dietary cholesterol absorption, both taking place mainly in the top cells of the duodenum or the proximal jejunum. Esterification of cholesterol also takes place mainly in the villus cells, while cholesterol synthesis is predominantly carried out in the crypt cells of the proximal duodenum and distal ileum. Cholesterol exchanges, which replace half of the cell cholesterol through the cell life, can be estimated at 3-4%.h-1 between plasma and mucosa cells, according to its location, i.e. 12-25 micrograms.h-1 (per mg cell DNA). In comparison, the cholesterol HDL or LDL uptake appears to be very low (0.02-0.06 and 0.2-0.6 microgram.h-1, respectively). Compartmentalization of cholesterol metabolism in the enterocyte can be suggested by different experimental data. The turnover of newly synthesized cholesterol is about 2-fold lower than that of exogenous (dietary) cholesterol. |
| Androgen biosynthesis from cholesterol to DHEA Miller, W. L. (2002), Mol Cell Endocrinol 198(1-2): 7-14. Abstract: Androgens and estrogens are made from dehydroepiandrosterone (DHEA), which is made from cholesterol via four steps. First, cholesterol enters the mitochondria with the assistance of the steroidogenic acute regulatory protein (StAR). Mutations in the StAR gene cause congenital lipoid adrenal hyperplasia. Second, within the mitochondria, cholesterol is converted to pregnenolone by the cholesterol side chain cleavage enzyme, P450scc. Third, pregnenolone undergoes 17alpha-hydroxylation by microsomal P450c17. Finally, 17-OH pregnenolone is converted to DHEA by the 17,20 lyase activity of P450c17. The ratio of the 17,20 lyase to 17alpha-hydroxylase activity of P450c17 determines the ratio of C21 to C19 steroids produced. This ratio is regulated post-translationally by at least three factors: the abundance of the electron-donating protein P450 oxidoreductase, the presence of cytochrome b(5), and the serine phosphorylation of P450c17. Study of these and related factors may yield important information about the pathophysiology of adrenarche and the polycystic ovary syndrome (PCOS). |
| Angiogenin activates phospholipase C and elicits a rapid incorporation of fatty acid into cholesterol esters in vascular smooth muscle cells Moore, F. and J. F. Riordan (1990), Biochemistry 29(1): 228-33. Abstract: Angiogenin activates the phosphoinositide-specific phospholipase C (PLC) in cultured rat aortic smooth muscle cells to yield a transient (30 s) peak of 1,2-diacylglycerol (DG) and inositol trisphosphate. Within 1 min, the DG level falls below that of the control and remains so for at least 20 min. A transient increase in monoacylglycerol indicates that depletion of DG may be the consequence of hydrolysis by DG lipase. In addition to these changes in second messengers, a rapid increase in incorporation of radiolabeled tracer into cellular cholesterol esters is observed. Stimulated cholesterol ester labeling is inhibited by preincubation with either the DG lipase inhibitor RHC 80267 or the acyl coenzyme A:cholesterol acyltransferase inhibitor Sandoz 58035. Cells prelabeled with 3Harachidonate show a sustained increase in labeling of cholesterol esters following exposure to angiogenin. In contrast, cells prelabeled with 3Holeate show only a transient elevation that returns to the basal level by 5 min. This suggests initial cholesterol esterification by oleate followed by arachidonate that is released by stimulation of the PLC/DG lipase pathway. |
| Angiotensin converting enzyme polymorphism is associated with severity of coronary heart disease and serum lipids (total cholesterol and triglycerides levels) in Japanese patients Suzuki, T., H. Yokota, et al. (1996), Coron Artery Dis 7(5): 371-5. Abstract: BACKGROUND: Much past research has concerned the relationship between coronary heart disease and the angiotensin converting enzyme (ACE) genotype, with many lines of evidence demonstrating polymorphism to be an independent risk factor for myocardial infarction. Interestingly, however, association of ACE polymorphism and severity of coronary artery stenosis according to racial background has recently been proposed. OBJECTIVE: To clarify the relationship between the ACE genotype and severity of coronary artery stenosis in Japanese patients. METHODS: In 36 consecutive patients undergoing coronary catheterization, comparative examination of coronary angiography findings with the ACE genotype was conducted. RESULTS: The severity of coronary artery stenosis indeed showed a relationship with the ACE genotype, with more severe coronary artery stenosis associated with the deletion (D) allele (P < 0.05). The serum lipids, total cholesterol and triglycerides levels, were also elevated in patients with the D allele (P < 0.05). CONCLUSION: We have provided further evidence that ACE polymorphism is associated with severity of coronary heart disease in a Japanese population. A possible relationship between serum lipids and the ACE genotype is also suggested. |
| Angiotensin II atherogenicity in apolipoprotein E deficient mice is associated with increased cellular cholesterol biosynthesis Keidar, S., J. Attias, et al. (1999), Atherosclerosis 146(2): 249-57. Abstract: Angiotensin II (Ang II) was shown to be an important risk factor for accelerated atherosclerosis. Inhibition of Ang II action on the arterial wall by blocking its production with angiotensin converting enzyme (ACE) inhibitors, or by blocking binding to its receptors on cells with antagonists was shown to attenuate atherogenesis in animal model of atherosclerosis. We questioned whether Ang II atherogenicity is related to a stimulatory effect of Ang II on macrophage cholesterol biosynthesis. Angiotensin II injected intraperitoneally once a day (0.1 ml of 10(-7) M per mouse) for a period of 30 days, to the apolipoprotein E deficient mice increased the atherosclerotic lesion area by 95% (P < 0.01 vs. control), compared to placebo-injected mice, with no significant effect on blood pressure or on plasma cholesterol levels. On using mouse peritoneal macrophages (MPMs) that were harvested after intraperitoneally injection of Ang II, an increased rate of cellular cholesterol biosynthesis (measured as incorporation of 3Hacetate into cholesterol) by up to 90% (P < 0.01 vs. control) was observed. In mice treated with the ACE inhibitor, Fosinopril (25 mg/kg per day) a reduction in their MPM's cholesterol synthesis by up to 70% (P < 0.01 vs. control) was obtained. In vitro studies in human monocyte-derived macrophages (HMDM), in MPMs from control BALB/c mice, and in J-774 A.1 macrophage-like cell line demonstrated up to 44, 34 and 30% stimulation of macrophage cholesterol biosynthesis, respectively, following cell incubation with 10(-7) M Ang II for 18 h at 37 degrees C. The stimulatory effect of Ang II on macrophage cholesterol biosynthesis could be related to its interaction with the macrophage AT1 receptor, as Losartan (10(-5) M), an AT1 blocker, but not PD 123319 (10(-5) M), an AT2 blocker, prevented the stimulatory effect on macrophage cholesterol synthesis. Furthermore, in cells that lack the AT1 receptor (RAW macrophages), Ang II did not increase cellular cholesterol synthesis. Ang II increased macrophage 3-hydroxy-3-methyl glutaryl CoA (HMG CoA) reductase mRNA levels in a dose dependent manner in J-774 A.1 macrophages and in MPM. Losartan, the AT1 receptor antagonist clearly attenuated this mRNA induction. We thus conclude that Ang II stimulation of macrophage cholesterol biosynthesis is related to its interaction with the AT1 receptor, followed by stimulation of macrophage HMG CoA reductase gene expression, which leads to increased cellular cholesterol biosynthesis, and can possibly result in macrophage cholesterol accumulation and foam cell formation. |
| Angiotensin II promotes selective uptake of high density lipoprotein cholesterol esters in bovine adrenal glomerulosa and human adrenocortical carcinoma cells through induction of scavenger receptor class B type I Cherradi, N., M. Bideau, et al. (2001), Endocrinology 142(10): 4540-9. Abstract: Angiotensin II is one of the main physiological regulators of aldosterone biosynthesis in the zona glomerulosa of the adrenal cortex. The hormone stimulates intracellular cholesterol mobilization to the mitochondrion for steroid biosynthesis. Here we have examined whether angiotensin II also modulates exogenous lipoprotein cholesterol ester supply to the steroidogenic machinery and whether this control is exerted on the selective transport of high density lipoprotein-derived cholesterol ester to intracellular lipid droplets through the scavenger receptor class B type I. In bovine adrenal glomerulosa and human NCI H295R adrenocortical carcinoma cells, high density lipoprotein stimulated steroid production. Angiotensin II pretreatment for 24 h potentiated this response. Fluorescence microscopy of cellular uptake of reconstituted high density lipoprotein containing a fluorescent cholesterol ester revealed an initial, time-dependent narrow labeling of the cell membrane followed by an intense accumulation of the fluorescent cholesterol ester within lipid droplets. At all time points, labeling was more pronounced in cells that had been treated for 24 h with angiotensin II. Fluorescence incorporation into cells was prevented by a monoclonal antibody directed against apolipoprotein A-I. Upon quantitative fluorometric determination, cholesterol ester uptake in angiotensin II-treated bovine cells was increased to 175 +/- 15% of controls after 2 h and to 260 +/- 10% after 4 h of exposure to fluorescent high density lipoprotein. The amount of scavenger receptor class B type I protein detected in cells treated with angiotensin II for 24 h reached 203 +/- 12% of that measured in control cells (n = 3, P < 0.01). In contrast, low density lipoprotein receptors were only minimally affected by angiotensin II treatment. This increase in scavenger receptor class B type I protein was associated with a 3-fold induction of scavenger receptor class B type I mRNA, which could be prevented by actinomycin D but not by cycloheximide. Similar results were obtained in the human adenocarcinoma cell line H295R. These observations show that angiotensin II regulates the scavenger receptor class B type I-mediated selective transport of lipoprotein cholesterol ester across the cell membrane as a major source of precursor for mineralocorticoid biosynthesis in both human and bovine adrenal cells. |
| Angiotensin II receptor antagonist treatment lowers plasma total and very low + low density lipoprotein cholesterol in Type 1 diabetic patients with albuminuria without affecting plasma cholesterol esterification and cholesteryl ester transfer Buter, H., A. van Tol, et al. (2000), Diabet Med 17(7): 550-2. |
| Angiotensin II reduces macrophage cholesterol efflux: a role for the AT-1 receptor but not for the ABC1 transporter Kaplan, M., M. Aviram, et al. (2002), Biochem Biophys Res Commun 290(5): 1529-34. Abstract: Impaired cellular cholesterol efflux in cells of the arterial wall is suggested to be involved in the pathogenesis of atherosclerosis. Since angiotensin II (Ang-II) is implicated in the development of atherosclerosis, the aim of the present study was to determine whether Ang-II could affect macrophage cholesterol efflux. Incubation of increasing concentrations of Ang-II (10(-10)-10(-7) M) with mouse peritoneal macrophages that were prelabeled with 3Hcholesterol led to a significant decrease in HDL-induced macrophage cholesterol efflux, by up to 70% compared to control cells incubated without Ang-II. Ang-II specifically increased the plasma membrane unesterified cholesterol content, the substrate for HDL-induced cholesterol efflux. The inhibitory effect of Ang-II on macrophage cholesterol efflux was found to be mediated by the angiotensin II type 1 (AT-1) receptor, since addition of the AT-1 antagonist Losartan completely blocked the inhibitory effect of Ang-II on the macrophage cholesterol efflux. We thus conclude that Ang-II atherogenicity may be related, at least in part, to its inhibitory effect on macrophage cholesterol efflux, thus leading to cellular cholesterol accumulation, the hallmark of early atherogenesis. |
| Angiotensin II-modified LDL is taken up by macrophages via the scavenger receptor, leading to cellular cholesterol accumulation Keidar, S., M. Kaplan, et al. (1996), Arterioscler Thromb Vasc Biol 16(1): 97-105. Abstract: The incidence of myocardial infarction is significantly higher in hypertensive patients with increased plasma concentration of angiotensin (Ang) II. Ang II was shown to bind to LDL in vitro, and in the present study we showed its binding to LDL in vivo. Ang II (10(-7) mol/L) was incubated with LDL for 3 hours at 37 degrees C, followed by reseparation of the modified lipoprotein (Ang II-LDL) and its incubation with J-774 A.1 macrophages. Binding of Ang II to LDL significantly increased the lipoprotein protein degradation (by 25%) and its cell association (by 75%) compared with nontreated LDL. Unlike Ang II-LDL, both Ang I-LDL and Ang III-LDL were taken up by macrophages similar to native LDL. The lipid composition and size of Ang II-LDL were similar to those of native LDL, and it was not aggregated. Ang II-LDL was not oxidized, as the contents of malondialdehyde and peroxides were not different from those found in native LDL. On heparin-Sepharose column chromatography, Ang II-LDL was eluted in the void volume, like acetylated LDL (Ac-LDL) and unlike native LDL, which binds to heparin. The cellular degradation of Ang II-125I-labeled LDL by J-774 A.1 macrophages of Ang II-125I-labeled LDL by J-774 A.1 macrophages was studied in the presence of a 50-fold excess of nonlabeled native LDL, Ang II-LDL, Ac-LDL, or oxidized LDL (Ox-LDL). Whereas native LDL had no effect on the degradation of Ang II-125I-LDL by the macrophages, Ac-LDL, Ox-LDL, and Ang II-LDL reduced the cellular uptake of the lipoprotein by 77%, 82%, and 87%, respectively. Similarly, fucoidin but not free Ang II reduced macrophage degradation of the labeled Ang II-LDL. We conclude that Ang II can modify LDL to a form that is not oxidized or aggregated but is still taken up at an enhanced rate by macrophages via the scavenger receptor. |
| Angiotoxicity and atherogenicity of cholesterol oxides Peng, S. K., B. Hu, et al. (1991), J Clin Lab Anal 5(2): 144-52. Abstract: Cholesterol in the diet can readily autoxidize and be absorbed and transported in plasma lipoproteins. Cholesterol oxides can also be endogenously produced in tissues via free-radical-induced reactions. Some cholesterol oxides, notably cholestane-3 beta, 5 alpha, 6 beta-triol and 25-hydroxycholesterol, have been shown to cause injury to vascular endothelial and smooth muscle cells, to alter LDL receptor function, to enhance cholesteryl ester accumulation, to inhibit prostacyclin production, and to induce experimental atherosclerosis alone or in combination with cholesterol. An epidemiological study examining relationships between atherosclerosis and plasma levels of cholesterol oxides as independent risk factors may provide additional insights regarding the roles of cholesterol oxides in atherogenesis. |
| Animal fat and cholesterol may have helped primitive man evolve a large brain Mann, F. D. (1998), Perspect Biol Med 41(3): 417-25. |
| Animal model for in vivo evaluation of cholesterol reduction by lactic Acid bacteria Taranto, M. P., G. Perdigon, et al. (2004), Methods Mol Biol 268: 417-22. Abstract: For many years, it has been recognized that elevated serum cholesterol is a risk factor associated with atherosclerosis and coronary heart disease, the latter being a major cause of death in Western countries. Numerous drugs that lower cholesterol have been used to treat hypocholesterolemic individuals. However, the undesirable side effects of these compounds have caused concerns about their therapeutic use. Ingestion of probiotic (beneficial for health) lactic acid bacteria (LAB) would possibly be a more natural method to decrease serum cholesterol in humans, as has been was reported.Previous studies have demonstrated that Lactobacillus reuteri administered in low doses has a hypocholesterolemic effect both therapeutically and preventively. One of the key studies in the development of a probiotic is to determine the minimal effective dose of live microorganisms that might be ingested without producing adverse effects (i.e., translocation) in the host.In this chapter, we describe an animal model that allows us to evaluate reduction in hypercholesterolemia by LAB and, also to determine the minimal dose of the microorganism, a critical step in the development of a safe probiotic product. |
| Animal model of spinal cord infarction induced by cholesterol embolization Saklayen, M. G., D. L. Goldstein, et al. (1995), Am J Med Sci 309(1): 49-52. Abstract: Though several animal models of ischemic brain infarction have been developed, no animal model of purely ischemic spinal cord infarction exists. In humans, such paralysis often occurs as a complication of aortic surgery. While working on an animal model of cholesterol embolic renal disease, the authors produced an animal model of ischemic spinal paralysis by direct intraaortic injection of cholesterol suspension. With histologic examination of spinal cords of the paralyzed rats, prominent cholesterol crystals were found obliterating the lumen of the anterior and/or posterior spinal arteries. Spinal cord infarction was seen most prominently in the lateral columns and anterior horns, though other areas also were affected. Permanent paraplegia developed in most rats, but transient paralysis developed in a few, followed by partial or full recovery. This model of spinal infarction in nonanesthetized rats can be used to study the pathophysiology and therapy of spinal infarction. |
| Animal models: new cholesterol raising and lowering nutrients Hassel, C. A. (1998), Curr Opin Lipidol 9(1): 7-10. Abstract: Most reports reviewed here have used animal models to investigate the cholesterolemic effects of phytochemicals, herbal extracts, probiotic microorganisms, and plant constituents, including fibers. These compounds represent examples of what are termed 'functional foods' in that they elicit physiologic responses with implications for chronic disease prevention. These reports are examined in light of criteria developed from animal model experiments investigating fatty acid effects in order to aid the task of appropriate extrapolation of the results to humans. |