[The genetic and biochemical mechanisms of the development of diabetic nephropathy in children]

The mechanisms responsible for the development of microangiopathies in type diabetes mellitus (DM1) are complex and under extensive study. Fresh data on the pathogenesis of DM1 make it possible to direct actual ways to the studies aimed at preventing the complications of this disease. The purpose of this study was to examine the contribution of the polymorphic types of the VNTR polymorphism of endothelial NO-synthase gene (NOS3) and the I/D polymorphism of angiotensin-converting enzyme (ACE), the status of the proteolytic systems and lipid metabolic disturbances to the development of diabetic neuropathy (DN). A total of 197 children Работа выполнена при финансовой поддержке гранта РГНФ № 00-06-00- 162а. who had DM1 in 1996-2002 were examined. Their mean age was 13.1 ±0.3 years. A control group comprised 32 apparently healthy children whose mean age was 12.8±0.1 years. DN was present in 44 children (19 boys and 25 girls). It has been established that allele A of endothelial NO-synthase is less common in diabetic patients with nephropathy (p < 0.05) and that it is a factor that reduces, while insignificantly, the risk for nephropathy (RR = 0.13). Analyzing the association with pathology by using the transmission/disequilibrium test has indicated the association of allele В of the gene NOS3 (TDT = 4.5, p - 0.034) and allele D of the gene ACE (TDT = 3.6, p < 0.05) with DN. The activity of plasma kallikrein was increased at the early stages of nephropathy (hyper-function). The higher activity of angiotensin-converting enzyme (57.0±2.9 μmol/min·l in the patients with nephropathy versus 38.1±2.8 μmol/min·/ in those without this disease) and the substantial suppression of α-proteinase inhibitor (21.1+-1.2 IU/ml in nephropathy at the stage of proteinuria versus 27.6±1.6 IU/ml without nephropathy) make a contribution to the development of nephropathy at the stages of microalbuminuria and proteinuria. ffyperlipidemia that manifests itself by the increased levels of cholesterol, triglycerides, and low-density lipoprotein cholesterol and by the decreased levels of high-density lipoprotein cholesterol is one of the mechanisms responsible for the development of DN in DM1.

Evidence for an exaggerated postprandial lipemia in chronic paraplegia

BACKGROUND/OBJECTIVE

Excessive delay in triglyceride (TG) metabolism after ingestion of dietary fat represents a significant cardiovascular disease (CVD) risk. The objective of this study was to compare the postprandial lipemic responses of individuals with paraplegia with those of healthy nondisabled individuals.

METHODS

The ability of 3 recreationally active individuals with paraplegia having normal fasting TG (mean = 103 mg/dL) to metabolize TG after ingestion of a high-fat test meal was compared with a previously published cohort of 21 recreationally active individuals without paraplegia (TG mean = 86 mg/dL) who underwent identical testing. The subjects with paraplegia had venous blood taken under fasting conditions, and then ingested a milkshake containing premium ice cream blended with heavy whipping cream (approximately 92% of calories from fat). Additional blood samples were obtained at 2, 4, and 6 hours after ingestion. The area under the curve (AUC) for TG clearance for both subject groups was measured with an area planimeter.

RESULTS

TG uptake for both groups was almost identical for the first 2 hours after ingestion. At 4 and 6 hours after ingestion, the TG levels were 50 and 35 mg/dL higher, respectively, in subjects with paraplegia than in nondisabled subjects. When corrected for small baseline differences in TG concentrations (16 mg/dL), the AUC was 46.5% greater for the group with paraplegia than in the nondisabled group. A near mirror association across time was observed between postprandial serum high-density lipoprotein cholesterol (HDL-C) and TG levels in subjects with paraplegia.

CONCLUSION

This case series finds an exaggerated postprandial lipemia (PPL) in persons with paraplegia with normal fasting TGs. This finding is the first evidence, in a small population, of an unreported potential CVD risk in persons with paraplegia.

Efficacy and safety of atorvastatin in South Asian patients with dyslipidemia: an open label noncomparative pilot study

BACKGROUND

Rates of coronary heart disease (CHD) mortality are 40% higher amongst South Asian men and women living in the UK compared with the general UK population. Despite an established excess CHD risk, little is known of the efficacy and safety of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) amongst South Asian migrants.

METHODS AND RESULTS

Hyperlipidemic South Asian patients (raised or uncontrolled low-density lipoprotein cholesterol [LDL-C]) were recruited from two UK centers (n = 33). After a five-week period, which included dietary advice, patients received atorvastatin 10 mg/d for five weeks to achieve a target LDL-C goal of < 3.0 mmol/L, titrated to 20 mg, 40 mg, or 80 mg for a further 12 weeks as required. Significant reductions in LDL-C levels from baseline were observed after 4 weeks' and 17 weeks' treatment with atorvastatin (> or = 33.6%; 26.0, 41.2). Overall, 81% (95% confidence interval [CI]: 62.5, 92.6%) achieved the target LDL-C after 4 weeks' treatment with 10 mg atorvastatin. Titration to a dose of more than 20 mg was required in only one patient (40 mg) at any point during the study. Nineteen patients reported at least one adverse event during the study; the majority were mild in severity and considered unrelated to atorvastatin.

CONCLUSIONS

Atorvastatin was effective in achieving target lipid levels and was well tolerated. Statin therapy for high-risk South Asian individuals is likely to benefit CHD outcomes, although further and larger prospective trials are required.

Lipoprotein(a): an elusive cardiovascular risk factor

Lipoprotein (a) [Lp(a)], is present only in humans, Old World nonhuman primates, and the European hedgehog. Lp(a) has many properties in common with low-density lipoprotein (LDL) but contains a unique protein, apo(a), which is structurally different from other apolipoproteins. The size of the apo(a) gene is highly variable, resulting in the protein molecular weight ranging from 300 to 800 kDa; this large variation may be caused by neutral evolution in the absence of any selection advantage. Apo(a) influences to a major extent metabolic and physicochemical properties of Lp(a), and the size polymorphism of the apo(a) gene contributes to the pronounced heterogeneity of Lp(a). There is an inverse relationship between apo(a) size and Lp(a) levels; however, this pattern is complex. For a given apo(a) size, there is a considerable variation in Lp(a) levels across individuals, underscoring the importance to assess allele-specific Lp(a) levels. Further, Lp(a) levels differ between populations, and blacks have generally higher levels than Asians and whites, adjusting for apo(a) sizes. In addition to the apo(a) size polymorphism, an upstream pentanucleotide repeat (TTTTA(n)) affects Lp(a) levels. Several meta-analyses have provided support for an association between Lp(a) and coronary artery disease, and the levels of Lp(a) carried in particles with smaller size apo(a) isoforms are associated with cardiovascular disease or with preclinical vascular changes. Further, there is an interaction between Lp(a) and other risk factors for cardiovascular disease. The physiological role of Lp(a) is unknown, although a majority of studies implicate Lp(a) as a risk factor.

Adiposity, dyslipidemia, and insulin resistance in mice with targeted deletion of phospholipid scramblase 3 (PLSCR3)

The phospholipid scramblases (PLSCR1 to PLSCR4) are a structurally and functionally unique class of proteins, which are products of a tetrad of genes conserved from Caenorhabditis elegans to humans. The best characterized member of this family, PLSCR1, is implicated in the remodeling of the transbilayer distribution of plasma membrane phospholipids but is also required for normal signaling through select growth factor receptors. Mice with targeted deletion of PLSCR1 display perinatal granulocytopenia due to defective response of hematopoietic precursors to granulocyte colony-stimulating factor and stem cell factor. To gain insight into the biologic function of another member of the PLSCR family, we investigated mice with targeted deletion of PLSCR3, a protein that like PLSCR1 is expressed in many blood cells but which, by contrast to PLSCR1, is also highly expressed in fat and muscle. PLSCR3(-/-) mice at 2 months of age displayed aberrant accumulation of abdominal fat when maintained on standard rodent chow, which was accompanied by insulin resistance, glucose intolerance, and dyslipidemia. Primary adipocytes and cultured bone-marrow-derived macrophages from PLSCR3(-/-) mice were engorged with neutral lipid, and adipocytes displayed defective responses to exogenous insulin. Plasma of PLSCR3(-/-) mice was elevated in non-high-density lipoproteins, cholesterol, triglycerides, nonesterified fatty acids, and leptin, whereas adiponectin was low. These data suggest that the expression of PLSCR3 may be required for normal adipocyte and/or macrophage maturation or function and raise the possibility that deletions or mutations affecting the PLSCR3(-/-) gene locus may contribute to the risk for lipid-related disorders in humans.

Sites of symptomatic gas retention during intestinal lipid perfusion in healthy subjects

BACKGROUND

Gas pooling within the gut may produce abdominal symptoms but the segment of the intestine responsible for gas retention is unknown. Our aim was to determine the role of the proximal and distal bowel in symptomatic gas accumulation using an experimental model of gas retention triggered by intraluminal lipids.

SUBJECTS

Sixteen healthy subjects.

METHODS

A gas mixture (N2, O2, and CO2 in venous proportions) was infused into the intestine at12 ml/min for three hours and gas evacuation was continuously measured via an anal cannula connected to a barostat. Abdominal perception and girth changes were measured at 10 minute intervals. Lipids (1 kcal/min) were simultaneously perfused either into the duodenum (n = 8) or into the ileum (n = 8). Each subject was studied twice on separate days, with gas infused into the jejunum or ileum.

RESULTS

Duodenal lipids produced retention of gas infused into the jejunum (646 (62) ml) but the volume retained was much smaller when gas was infused directly into the ileum (262 (90) ml; p<0.05). The effects on gas retention were even more pronounced during ileal perfusion of lipids (1546 (184) ml during jejunal gas infusion and 847 (142) ml during ileal gas infusion; p<0.05). Abdominal distension correlated with the volume of gas retained (r = 0.87; p<0.001). Healthy subjects tolerated gas retention, and significant symptoms (score 3.7 (0.8)) developed only during jejunal gas infusion plus ileal lipid perfusion when gas retention was very large.

CONCLUSION

Intraluminal lipids induce intestinal gas retention, predominantly acting on the proximal small bowel.

Meta-analysis of large randomized controlled trials to evaluate the impact of statins on cardiovascular outcomes

AIMS

Since 2002, there have been five major outcome trials of statins reporting findings from more than 47,000 subjects. As individual trial results differed, we performed a meta-analysis to ascertain the effectiveness and safety of statins overall and in subgroups. The aim of the study was to estimate the effect of statins on major coronary events and strokes, all-cause mortality and noncardiovascular mortality, and in different subgroups.

METHODS

PubMed was searched for trials published in English. Randomized placebo-controlled statin trials with an average follow up of at least 3 years and at least 100 major coronary events were included. For each trial, the statin used, number and type of subjects, proportion of women, mean age and follow up, baseline and change in lipid profile, cardiovascular and non-cardiovascular outcomes were recorded.

RESULTS

Ten trials involving 79,494 subjects were included in the meta-analysis. Due to heterogeneity, ALLHAT-LLT was excluded from some analyses. Statin therapy reduced major coronary events by 27% (95%CI 23, 30%), stroke by 18% (95%CI 10, 25%) and all-cause mortality by 15% (95%CI 8, 21%). There was a 4% (95%CI -10, 3%) nonsignificant reduction in noncardiovascular mortality. The reduction in major coronary events is independent of gender and presence of hypertension or diabetes. The risk reduction was greater in smokers (P < 0.05). Coronary events were reduced by 23% (95%CI 18, 29%) in pravastatin trials and 29% (95%CI 25, 33%) in five trials using other statins. Pravastatin reduced strokes by 12% (95%CI 1, 21%) whilst other statins reduced strokes by 24% (95%CI 16, 32%) (P = 0.04).

CONCLUSIONS

Statins reduce coronary events, strokes and all-cause mortality without increasing noncoronary mortality. The benefits accrue in men and women, hypertensives and normotensives, diabetics and nondiabetics, and particularly in smokers. Pravastatin appears to have less impact on strokes.

Efficacy of orlistat as an adjunct to behavioral treatment in overweight African American and Caucasian adolescents with obesity-related co-morbid conditions

This pilot study compared the efficacy of orlistat as an adjunctive treatment for obesity between African American and Caucasian adolescents. Twenty obese adolescents with obesity-related co-morbid conditions underwent measurements of body composition, glucose homeostasis by frequently sampled intravenous glucose tolerance test (FSIGT), and fasting lipids before and after 6 months treatment with orlistat 120 mg tid in conjunction with a comprehensive behavioral program. Weight (p < 0.05), BMI (p < 0.001), total cholesterol (p < 0.001), LDL cholesterol (p < 0.001), fasting insulin (p < 0.02) and fasting glucose (p < 0.003) were lower after treatment. Insulin sensitivity, measured during the FSIGT, improved significantly (p < 0.02), as did fasting indices such as the homeostasis model assessment for insulin resistance (p < 0.01). African American subjects exhibited significantly less improvement in weight (p < 0.05), BMI (p < 0.01), waist circumference (p = 0.03), and insulin sensitivity (p = 0.05). Improvements in cholesterol were not significantly different between African Americans and Caucasians. We conclude that Caucasians lost more weight and had greater improvements in insulin sensitivity than African Americans, but both exhibited improvements in plasma lipids. The true benefit of orlistat treatment over a comprehensive behavioral program remains to be determined in placebo-controlled trials.

Lipid composition of Botrytis cinerea and inhibition of its radiolabelling by the fungicide iprodione

•  Botrytis cinerea is an important plant pathogen that causes grey mould in over 200 hosts. It is often controlled by dicarboximides, which have various proposed mechanisms of action, including effects on lipids. Here we have examined the effect of one dicarboximide, iprodione, on lipid metabolism. •  B. cinerea, cultured in malt extract media, was challenged with iprodione and its lipids extracted, separated by TLC, and analysed by GLC. Lipid metabolism was followed using [1-¹⁴ C]acetate. •  Triacylglycerol was the major nonpolar and phosphatidylcholine the main polar lipid in B. cinerea. Linoleate, followed by α-linolenate, were the major fatty acids and most lipid classes had compositions broadly similar to the total fatty acid pattern. Iprodione, at concentrations causing a cessation of growth (5 µM) caused a decrease in polar lipid but not total nonpolar lipid labelling. Within the nonpolar lipids, DAG was better labelled. •  The data show that iprodione had a selective effect on lipid metabolism. The altered pattern of labelling suggested that choline (ethanolamine) phosphotransferase would be worth investigating as a primary site of action.

Palmitoylethanolamide increases after focal cerebral ischemia and potentiates microglial cell motility

Focal cerebral ischemia (FCI) induces rapid neuronal death in the ischemic core, which gradually expands toward the penumbra, partly as the result of a neuroinflammatory response. It is known that propagation of neuroinflammation involves microglial cells, the resident macrophages of the brain, which are highly motile when activated by specific signals. However, the signals that increase microglial cell motility in response to FCI remain mostly elusive. Here, we tested the hypothesis that endocannabinoids mediate neuroinflammation propagation by increasing microglial cell motility. We found that, in mouse cerebral cortex, FCI greatly increases palmitoylethanolamide (PEA), only moderately increases anandamide [arachidonylethanolamide (AEA)], and does not affect 2-arachidonoylglycerol levels. We also found that PEA potentiates AEA-induced microglial cell migration, without affecting other steps of microglial activation, such as proliferation, particle engulfment, and nitric oxide production. This potentiation of microglial cell migration by PEA involves reduction in cAMP levels. In line with this, we provide evidence that PEA acts through Gi/o-coupled receptors. Interestingly, these receptors engaged by PEA are pharmacologically distinct from CB1 and CB2 cannabinoid receptors, as well as from the WIN and abn-CBD (abnormal-cannabidiol) receptors, two recently identified cannabinoid receptors. Our results show that PEA and AEA increase after FCI and synergistically enhance microglial cell motility. Because such a response could participate in the propagation of the FCI-induced neuroinflammation within the CNS, and because PEA is likely to act through its own receptor, a better understanding of the receptor engaged by PEA may help guide the search for improved therapies against neuroinflammation.

Physical activity, high density lipoprotein cholesterol and other lipids levels, in men and women from the ATTICA study

BACKGROUND

Physical activity has long been associated with reduced risk of coronary heart disease (CHD). In this work we evaluated the effect of physical activity on lipid levels, in a sample of cardiovascular disease free people.

METHODS

The ATTICA study is a population-based cohort that has randomly enrolled 2772 individuals, stratified by age-gender (according to the census 2001), from the greater area of Athens, during 2001-2002. Of them, 1376 were men (45 +/- 12 years old, range: 18-86) and 1396 women (45 +/- 13 years old, range: 18-88). We assessed the relationship between physical activity status (measured in kcal/min expended per day) and several lipids, after taking into account the effect of several characteristics of the participants.

RESULTS

578 (42%) men and 584 (40%) women were classified as physically active. Compared to sedentary physically active women had significantly lower levels of total serum cholesterol (p < 0.05), LDL (p < 0.05) and oxidized LDL cholesterol (p < 0.05), triglycerides (p < 0.05), apolipoprotein B (p < 0.05), and higher levels of HDL cholesterol (p < 0.05) and apolipoprotein A1 (p < 0.05). Similar associations were observed in men, but the benefits did not reach statistical significance. However, when we adjusted for age, smoking habits and body mass index, physical activity was only significantly associated with higher HDL-cholesterol (p < 0.05) and apolipoprotein A1 (p < 0.05) levels, in women, but not in men.

CONCLUSIONS

Substantial independent increases in HDL-cholesterol and apolipoprotein A1 concentrations were observed in women, but not in men, in a Mediterranean cohort.

The power of statins: aggressive lipid lowering

A large body of evidence has demonstrated that reductions in low-density lipoprotein cholesterol (LDL-C) decrease the risk of coronary heart disease (CHD) and related adverse events. The greatest reductions in morbidity and mortality are attained in higher-risk patients, suggesting that targeting this group can maximize the cost-effectiveness of statins, since fewer patients need to be treated to prevent one event. High-risk individuals (those with preexisting CHD or CHD risk equivalents) require aggressive lipid lowering to achieve the stringent LDL-C goal levels established by the third report of the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III). The hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, have assumed the central role in this setting because of their superior ability to reduce LDL-C across the spectrum of CHD risk. Rosuvastatin, a new agent in this class, reduces LDL-C to a significantly greater degree than atorvastatin, pravastatin, or simvastatin. The more aggressive goals put forward since ATP I (1987) have heightened interest in more efficacious statins. As a result, simvastatin, atorvastatin, and now rosuvastatin have been developed, adding sequentially greater LDL-C-reducing capacity for the physician. Substantially more patients, particularly high-risk patients, are thereby able to achieve NCEP ATP III target LDL-C levels with rosuvastatin. Other cholesterol-lowering drugs (bile acid sequestrants, niacin, plant stanols, and fibrates) are much less effective at lowering LDL-C and are much less well tolerated but may be useful when combined with statins. A novel class of agents, cholesterol transport inhibitors, have recently become available. These and other new agents hold promise to help achieve ATP III goals when used in combination regimens initiated with a statin.

Alcohol, oxidative stress, and free radical damage

Reactive oxygen species (ROS) are small, highly reactive, oxygen-containing molecules that are naturally generated in small amounts during the body's metabolic reactions and can react with and damage complex cellular molecules such as fats, proteins, or DNA. Alcohol promotes the generation of ROS and/or interferes with the body's normal defense mechanisms against these compounds through numerous processes, particularly in the liver. For example, alcohol breakdown in the liver results in the formation of molecules whose further metabolism in the cell leads to ROS production. Alcohol also stimulates the activity of enzymes called cytochrome P450s, which contribute to ROS production. Further, alcohol can alter the levels of certain metals in the body, thereby facilitating ROS production. Finally, alcohol reduces the levels of agents that can eliminate ROS (i.e., antioxidants). The resulting state of the cell, known as oxidative stress, can lead to cell injury. ROS production and oxidative stress in liver cells play a central role in the development of alcoholic liver disease.

Dangerous byproducts of alcohol breakdown--focus on adducts

Alcohol breakdown in the liver results in the generation of the reactive molecule acetaldehyde and, as a byproduct, highly reactive oxygen-containing molecules known as oxygen radicals. Both acetaldehyde and oxygen radicals can interact with proteins and other complex molecules in the cell, forming hybrid compounds called adducts. Other adducts are formed with aldehyde molecules, which are produced through the interaction of oxygen radicals with lipids in the cells. Adduct formation impedes the function of the original proteins participating in the reaction. Moreover, the adducts may induce harmful immune responses. Both of these effects may account for some of the damage observed in alcoholic liver disease. Adduct formation has been shown to occur in the livers of humans and animals consuming alcohol and to start and predominate in those liver regions that show the first signs of liver damage.

Abscisic acid modifies the changes in lipids brought about by water stress in the moss Atrichum androgynum

•  Mosses are particularly able to withstand drought stress. Moreover, abscisic acid (ABA), which is intimately involved during stress in higher plants, has also been implicated in bryophytes. Because membrane damage is a common feature of drought stress, we have studied changes in lipid composition during desiccation and rehydration of the moss Atrichum androgynum and the effect of exogenous ABA on these processes. •  In order to correlate any membrane changes with drought stress, we analysed different lipid classes by thin-layer chromatography, fatty acid composition by gas-liquid chromatography and lipid peroxidation. •  Water stress caused changes in phosphoglyceride composition consistent with an activation of phospholipase D and of phosphatidylinositol metabolism. Recovery of phosphoglyceride composition towards original levels occurred during rehydration and ABA treatment reduced the overall extent of changes. Reduction in thylakoid lipids and chlorophyll coincided with loss of photosynthesis. •  The data show that mosses respond to drought stress similarly to higher plants and that ABA may reduce membrane damage by diminishing the lipid changes.

Atorvastatin inhibits hypercholesterolemia-induced cellular proliferation and bone matrix production in the rabbit aortic valve

BACKGROUND

Despite the common occurrence of aortic stenosis, the cellular causes of the disorder are unknown, in part because of the absence of experimental models. We hypothesized that atherosclerosis and early bone matrix expression in the aortic valve occurs secondary to experimental hypercholesterolemia and that treatment with atorvastatin modifies this transformation.

METHODS AND RESULTS

To test this hypothesis, we developed an experimental hypercholesterolemic rabbit model. New Zealand White rabbits (n=48) were studied: group 1 (n=16), normal diet; group 2 (n=16), 1% (wt/wt) cholesterol diet; and group 3 (n=16), 1% (wt/wt) cholesterol diet plus atorvastatin (3 mg/kg per day). The aortic valves were examined with hematoxylin and eosin stain, Masson trichrome, macrophage (RAM 11), proliferation cell nuclear antigen (PCNA), and osteopontin immunostains. Cholesterol and highly sensitive C-reactive protein (hsCRP) serum levels were obtained by standard assays. Computerized morphometry and digital image analysis were performed for quantifying PCNA (% area). Electron microscopy and immunogold labeling were performed for osteopontin. Semiquantitative RT-PCR was performed for the osteoblast bone markers [alkaline phosphatase, osteopontin, and osteoblast lineage-specific transcription factor (Cbfa-1)]. There was an increase in cholesterol, hsCRP, PCNA, RAM 11, and osteopontin and osteoblast gene markers (alkaline phosphatase, osteopontin, and Cbfa-1) in the cholesterol-fed rabbits compared with control rabbits. All markers except hsCRP were reduced by atorvastatin.

CONCLUSIONS

These findings of increased macrophages, PCNA levels, and bone matrix proteins in the aortic valve during experimental hypercholesterolemia provide evidence of a proliferative atherosclerosis-like process in the aortic valve associated with the transformation to an osteoblast-like phenotype that is inhibited by atorvastatin.

Walking exercise and its relationship to serum lipids in Japanese

This study sought to investigate the effects of walking on serum lipids among the middle-aged and elderly. The subject group included 3312 adult Japanese who underwent a routine health examination at Yukuhashi city, Fukuoka Prefecture, in 1998. The amount of walking in which the subjects engaged and other lifestyle characteristics were examined by a self-reported questionnaire. Analyses of variance were performed to calculate adjusted means of total cholesterol, HDL cholesterol, triglyceride, and LDL cholesterol using walking time as the level of a factor. Multiple logistic regression analyses were also performed to estimate odds ratios and 95% confidence intervals for unfavorable lipid profiles. For both sexes, the adjusted mean for total and LDL cholesterol was higher in individuals who walked than in those who did not walk, and also individuals who walked had higher odds ratios for higher total cholesterol levels than those who did not walk. For men, the adjusted mean for HDL cholesterol was higher in individuals who walked than in those who did not walk. No significant difference was observed in triglyceride or the ratio of total cholesterol to HDL cholesterol between individuals who walked and those who did not walk. This suggests that walking exercise may not achieve the beneficial effect on lipids profiles among middle-aged/older Japanese.

Comparison of leaf construction costs in woody species with differing leaf life-spans in contrasting ecosystems

•  The construction costs (CC) are reported of leaves from 162 wild woody species from 14 contrasting environments (desert to rain forest) and with different leaf life-spans. •  Calorimetric methods were used to estimate the CC of deciduous, semideciduous and evergreen leaves. •  Leaf CC showed a wide range (78%) between species, and deciduous species showed a slightly lower CC (6%) than both semideciduous and evergreen species. Mean leaf CC differed between ecosystems, with the highest and lowest CC in the tundra and rain forest, respectively. Leaf CC was positively correlated with lipid concentration. Leaf size (log) and specific leaf area (SLA, leaf area per leaf dry mass) were negatively correlated with leaf CC. Leaf CC did not show differences between different leaf life-spans or ecosystems when leaf size (log) or SLA were included as covariates. •  The small differences in leaf CC among leaf life-span types and ecosystems (6% and 23%, respectively) suggest that SLA is more important in determining differences in the carbon balance between species than leaf CC. Leaf size is shown to be an important trait associated with other leaf characteristics. ABBREVIATIONS: A, ash concentration; CC, construction cost per unit dry mass; CC_A , construction cost per unit area; Eg, growth efficiency; Hc, ash free heat of combustion; N, nitrogen; SLA, specific leaf area.

Enhanced endothelium-dependent vasodilation in Fabry disease

BACKGROUND AND PURPOSE

Fabry disease is an X-linked lysosomal storage disease secondary to deficiency of alpha-galactosidase A with resulting glycolipid accumulation, particularly globotriaosylceramide in arterial smooth muscle and endothelial cells. A systemic vasculopathy, including early-onset stroke, is prevalent without a clear pathogenesis.

METHODS

Seventeen normotensive and normocholesterolemic hemizygous Fabry patients (aged 21 to 49 years) and 13 control subjects (aged 21 to 48 years) were investigated by venous plethysmography, allowing assessment of forearm blood flow. Plethysmographic measurements were obtained at baseline and during intra-arterial infusion of acetylcholine and sodium nitroprusside both with and without N(G)-monomethyl-L-arginine (L-NMMA).

RESULTS

Forearm blood flow was significantly higher in patients than in control subjects at all 3 acetylcholine doses (P=0.014). Patients had a greater response to acetylcholine even after the addition of L-NMMA (P=0.036).

CONCLUSIONS

These results demonstrate an increased endothelium-mediated vascular reactivity in Fabry disease. The increased vessel response to acetylcholine with and without L-NMMA suggests altered functionality of non-NO endothelium-dependent vasodilatory pathways.

Arterial Hypertension Is Associated with Increased Serum Lipoprotein(a) Levels in End-Stage Renal Disease Patients

In addition to disorders in lipoprotein metabolism, several other factors are involved in the development of atherosclerotic changes in end-stage renal disease (ESRD) patients. One of these is arterial hypertension. We evaluated serum lipids-total cholesterol (TC), triglycerides (TG), apolipoproteins (A_I , A _II , B, E), lipoprotein(a) [Lp(a)]-in 109 ESRD patients on dialysis [46 on hemodialysis (HD); 63 on continuous ambulatory peritoneal dialysis (CAPD)] and in 45 hyperlipidemic patients without renal failure (HL group). Dialysis patients were divided in two groups. Group A included 42 hypertensive patients (mean age: 62.3 ± 15.5 years) whose blood pressure (BP) was satisfactorily controlled with anti-hypertensive medications. Group B included 67 non hypertensive patients (mean age: 66.6 ± 11.9 years). Levels of Lp(a) were significantly higher in both the HD (p = 0.001) and the CAPD (p < 0.05) patients as compared with the HL group. When the HD and CAPD groups were divided into hypertensive and non hypertensive patients, Lp(a) levels were significantly higher in the hypertensive patients; this difference was not observed among non renal failure patients. These results indicate that arterial hypertension is associated with elevated Lp(a) serum levels in ESRD patients undergoing either HD or CAPD.

The role of dyslipidemia and statins in venous thromboembolism

Recent studies have proposed an association between hyperlipidemia and venous thromboembolism (VTE). We review the epidemiological evidence linking dyslipidemia with VTE and examine several possible underlying mechanisms. We discuss the possible role of HMG CoA reductase inhibitors (statins) in the prevention and treatment of VTE and suggest future directions for research.

Energy Metabolism and Survival of the Infective Juveniles of Steinernema carpocapsae under Oxygen-Deficient Conditions

Energy metabolism and its relation to survival of the infective juveniles (IJ) of S. carpocapsae under anaerobic and oxygen-deficient conditions were studied by monitoring changes in survival rate, levels of key energy reserve materials, oxygen consumption, and respiratory quotient (RQ). The effects of various factors on the survival of IJ under anaerobic conditions were also investigated. Under anaerobic conditions, the IJ were inactivated but could survive for several days in an immobile state, using the carbohydrate reserves glycogen and trehalose for energy supply. The survival time of IJ was mainly dependent on the availability of energy supply, which, in turn, was influenced by factors such as temperature and metabolic by-products. Surviving, anaerobically incubated IJ fully recovered upon return to aerobic conditions. Recovering IJ were characterized by regaining mobility and restoration of carbohydrate reserves consumed during the anaerobic period. Carbohydrate reserves were restored by conversion from lipid reserves and possibly from anaerobic metabolic by-products. The infectivity of IJ recovered from the anaerobic state was not affected. At 1% oxygen level, IJ were also immobile and mainly depended on carbohydrate reserves for energy supply and the RQ was greater than 1. However, some oxygen was consumed; the survival time of these IJ was shorter than those kept in natural air but longer than those under anaerobic conditions. When IJ were incubated at oxygen levels of 3% to 21%, the RQs were maintained at 0.7 to 0.8. Oxygen consumption rates and the reduction in both mean dry weight and lipid levels were proportional to oxygen levels while the survival time of IJ was inversely proportional to oxygen levels.

Dermatophyte lipids-Composition and regulation of phospholipids

This review presents the extensive work carried out on lipid components of dermatophytes, their biosynthesis, turnover and regulation. It emerges from the work done so far that the pathways of lipid biosynthesis/ degradation and the lipid composition in dermatophytes are similar to those in yeasts and other fungi. Second messengers (Ca(2+), cAMP) were demonstrated to have a regulatory role in phospholipid metabolism and they mainly act by stimulating Ca(2+)/CaM or cAMP dependent protein kinase(s). Both these kinases were purified and characterized inMicrosporum gypseum. Further work is being carried out to elucidate the molecular mechanism of regulation of phospholipid metabolism by these second messengers.

Human CD1b and CD1c isoforms survey different intracellular compartments for the presentation of microbial lipid antigens

CD1b and CD1c are antigen-presenting molecules that mediate recognition of bacterial lipids by T cells, but it is currently not known whether these two molecules are redundant or are specialized to perform different immunological functions. Here, we show that the distribution of CD1c in human dendritic cells was characterized by a high ratio of cell surface to intracellular molecules, whereas CD1b showed a reciprocal pattern of distribution. In contrast to the accumulation of CD1b in lysosomal major histocompatibility complex class II compartments, intracellular CD1c molecules accumulated in other endocytic compartments, most likely early and late endosomes. Deletion of the cytoplasmic tail of CD1c, containing a tyrosine-based internalization motif, abolished most of its intracellular localization. Functional studies using T cells specific for defined lipid antigens revealed that in contrast to CD1b-mediated antigen presentation, antigen presentation by CD1c was resistant to drugs inhibiting endosomal acidification and was independent of endosomal localization of CD1c. Taken together, these results support the hypothesis that CD1b and CD1c are specialized to survey the lipid content of different intracellular compartments.

Role of a new mammalian gene family in the biosynthesis of very long chain fatty acids and sphingolipids

Whereas the physiological significance of microsomal fatty acid elongation is generally appreciated, its molecular nature is poorly understood. Here, we describe tissue-specific regulation of a novel mouse gene family encoding components implicated in the synthesis of very long chain fatty acids. The Ssc1 gene appears to be ubiquitously expressed, whereas Ssc2 and Cig30 show a restricted expression pattern. Their translation products are all integral membrane proteins with five putative transmembrane domains. By complementing the homologous yeast mutants, we found that Ssc1 could rescue normal sphingolipid synthesis in the sur4/elo3 mutant lacking the ability to synthesize cerotic acid (C(26:0)). Similarly, Cig30 reverted the phenotype of the fen1/elo2 mutant that has reduced levels of fatty acids in the C(20)-C(24) range. Further, we show that Ssc1 mRNA levels were markedly decreased in the brains of myelin-deficient mouse mutants known to have very low fatty acid chain elongation activity. Conversely, the dramatic induction of Cig30 expression during brown fat recruitment coincided with elevated elongation activity. Our results strongly implicate this new mammalian gene family in tissue-specific synthesis of very long chain fatty acids and sphingolipids.

The Influence of Potato Cultivar on Lipid Content and Fecundity of Bolivian and British Populations of Globodera rostochiensis

The influence of host cultivar on the lipid levels provided by a female to her progeny was investigated with Oil Red O stain and a quantitative image analyzer. A population of Globodera rostochiensis was multiplied at Toralapa Field Station in Bolivia on 25 different potato cultivars grown in that country. The mean neutral lipid content of newly formed second-stage juveniles varied significantly with cultivar over a 200% range. The corresponding range was only 18% and 28% for the same Bolivian and a UK population of G. rostochiensis, respectively, when both completed reproduction concurrently on 10 pot-grown European cultivars in the United Kingdom. Egg numbers per female varied with host for Bolivian cultivars that lack known partial resistance to Globodera spp. There was a 15-fold range between the most and least fecund nematode-host combinations (Kosi and Gendarme). The Bolivian G. rostochiensis population showed only a 2-fold range in mean eggs per cyst when grown on European cultivars in the UK. The fatty acid profiles of lipids from Bolivian G. rostochiensis cysts reared on Bolivian potato cultivars were dominated by C(20) (37-64%) and C(18) (28-46%) fatty acids and ranged from C(14) to C(22). The three major fatty acids detected were C(20:4:), C(20:1), and C(18:1). Few differences between cultivars were observed. For a UK population of G. rostochiensis reared on ssp. tuberosum, higher relative percentages of C(18) and monounsaturated fatty acids and lower relative percentages of C(20) and polyunsaturated fatty acids were found.

Nonmonotonous Changes in Metabolic Parameters of Tissues and Cells under Action of Ionizing Radiation on Animal

A nonmonotonous relationship between changes of metabolic parameters of tissues and cells of animal and radiation dose were discussed. Under acute irradiation of animals the nonmonotonous dose-response curve for metabolic parameters of tissues and cells were found. The nonmonotonous dose-response curves of metabolic and functional tissues and cells parameters were also revealed upon chronic irradiation of animals at a low dose-rate. The nonmonotonous shape of dose-response curves may be explained on the basis of nonmonotonous kind of the time-course of metabolic response after irradiation. Living cells were supposed to possess a fundamental property in response to action of different stress agents by nonmonotonous changes of cell metabolism. This response was damping in time oscillation of the value of metabolic parameters around the normal level. Amplitudes and periods of oscillations in these changes of metabolic parameters could be observed. In case of chronic irradiation at a low dose-rate the metabolic and functional parameters showed some modified oscillation during irradiation. The nonmonotonous type of changes in metabolic and functional parameters of tissue and cell by chronic low dose-rate irradiation threw some new light on the peculiarities of biological effects of chronic irradiation.

Electrospray ionization tandem mass spectrometry (ESI-MS/MS) analysis of the lipid molecular species composition of yeast subcellular membranes reveals acyl chain-based sorting/remodeling of distinct molecular species en route to the plasma membrane

Nano-electrospray ionization tandem mass spectrometry (nano-ESI-MS/MS) was employed to determine qualitative differences in the lipid molecular species composition of a comprehensive set of organellar membranes, isolated from a single culture of Saccharomyces cerevisiae cells. Remarkable differences in the acyl chain composition of biosynthetically related phospholipid classes were observed. Acyl chain saturation was lowest in phosphatidylcholine (15.4%) and phosphatidylethanolamine (PE; 16.2%), followed by phosphatidylserine (PS; 29.4%), and highest in phosphatidylinositol (53.1%). The lipid molecular species profiles of the various membranes were generally similar, with a deviation from a calculated average profile of approximately +/- 20%. Nevertheless, clear distinctions between the molecular species profiles of different membranes were observed, suggesting that lipid sorting mechanisms are operating at the level of individual molecular species to maintain the specific lipid composition of a given membrane. Most notably, the plasma membrane is enriched in saturated species of PS and PE. The nature of the sorting mechanism that determines the lipid composition of the plasma membrane was investigated further. The accumulation of monounsaturated species of PS at the expense of diunsaturated species in the plasma membrane of wild-type cells was reversed in elo3Delta mutant cells, which synthesize C24 fatty acid-substituted sphingolipids instead of the normal C26 fatty acid-substituted species. This observation suggests that acyl chain-based sorting and/or remodeling mechanisms are operating to maintain the specific lipid molecular species composition of the yeast plasma membrane.

Effect of apolipoprotein E gene Hha I restricting fragment length polymorphism on serum lipids in cholecystolithiasis

AIM: To investigate the role of apolipoprotein E (apoE) polymorphism in the lithogenesis of gallstone and the hereditary pathogenesis of the disease.

METHODS: Polymerase chain reaction (PCR) was used to study apoE phenotypes and allele frequencies in patients with gallstones and control, and the fasting serum lipids of subjects were also measured by enzymatic methods.

RESULTS: The levels of triglyceride (TG) and very low density lipoprotein cholesterol (VLDL-C) were much higher in E_2/3 patients than that in E_2/3 control. E_3/3 patients were accompanied with remarkably low levels of high density lipoprotein cholesterol(HDL-C) and its subforms. But in E_3/4 patients there were only slight changes in levels of VLDL-C and low density lipoprotein cholesterol (LDL-C).

CONCLUSION: Different apoE phenotype patients with gallstones have different cheracteristics of dyslipidemia and the average level of serum lipids in patients with gallstones are higher than subjects without gallstones in the same apoE gene phenotype. ε2 allele is possibly one of the dangerous factors in the lithogenesis of chole-cystolithiasis.

Inhibition of caspases inhibits the release of apoptotic bodies: Bcl-2 inhibits the initiation of formation of apoptotic bodies in chemotherapeutic agent-induced apoptosis

During apoptosis, the cell actively dismantles itself and reduces cell size by the formation and pinching off of portions of cytoplasm and nucleus as "apoptotic bodies." We have combined our previously established quantitative assay relating the amount of release of [3H]-membrane lipid to the degree of apoptosis with electron microscopy (EM) at a series of timepoints to study apoptosis of lymphoid cells exposed to vincristine or etoposide. We find that the [3H]-membrane lipid release assay correlates well with EM studies showing the formation and release of apoptotic bodies and cell death, and both processes are regulated in parallel by inducers or inhibitors of apoptosis. Overexpression of Bcl-2 or inhibition of caspases by DEVD inhibited equally well the activation of caspases as indicated by PARP cleavage. They also inhibited [3H]-membrane lipid release and release of apoptotic bodies. EM showed that cells overexpressing Bcl-2 displayed near-normal morphology and viability in response to vincristine or etoposide. In contrast, DEVD did not prevent cell death. Although DEVD inhibited the chromatin condensation, PARP cleavage, release of apoptotic bodies, and release of labeled lipid, DEVD-treated cells showed accumulation of heterogeneous vesicles trapped in the condensed cytoplasm. These results suggest that inhibition of caspases arrested the maturation and release of apoptotic bodies. Our results also imply that Bcl-2 regulates processes in addition to caspase activation.

Hyperlipidemia and obesity among diabetics at jubail miiltary hospital

OBJECTIVE

Evaluate the pattern of dyslipidemia and obesity among diabetics, attending the Primary Care Clinic.

SUBJECTS AND METHODS

All diabetics (282) registered in the Primary Care Clinic of the Armed Forces Hospital at King Abdulaziz Naval Base, Jubail, Eastern Saudi Arabia, were interviewed by primary care doctors. Weight and height were recorded; fasting blood glucose and cholesterol levels were measured after 12-hour fasting.

RESULTS

The study revealed that among 89.7% type 2 and 10.3% type 1 diabetes mellitus, 22.7% had a normal Body Mass Index (BMI) 40.8% were overweight, and 36.5%, obese. Females had a significantly higher BMI than males (P<0.001). Total cholesterol was more than normal in 26%, LDL in 27% and Triglycerides in 11% but HDL lower than normal in 38%. However, mixed hyperlipidemia was seen in 5% of the study population.

CONCLUSION

Obesity and dyslipidemia were high among diabetic patients and special attention is required in prevention and treatment.

Effect of two aspirin pretreatment regimens on niacin-induced cutaneous reactions

OBJECTIVE

To compare the effects of pretreatment with two aspirin regimens and placebo on niacin-induced cutaneous reactions.

DESIGN

Randomized, double-blind, placebo-controlled, crossover study.

SETTING

Internal medicine clinic in an academic health center.

PARTICIPANTS

Forty-two healthy subjects (22 males and 20 females) between the ages of 35 and 65 (mean age 44.2 years) were recruited and completed the study. Subjects received aspirin 325 mg, aspirin 650 mg, and placebo for 4 consecutive days, and on the fourth day also ingested 500 mg of immediate-release niacin 30 minutes after taking aspirin or placebo. They reported the intensity of flushing, headache, pruritus, tingling, and warmth on a 10-cm visual analogue scale. Reactions were evaluated at time 0 (before the niacin dose), and at 15, 30, 60, and 120 minutes following the niacin dose. Cutaneous reactions were compared at each evaluation time and scored by two other methods. The peak intensity was the highest score recorded at any of the four evaluation times after niacin administration. An intensity-time factor was calculated by totaling the scores of each of the four evaluation times.

MEASUREMENT AND MAIN RESULTS

The symptom scores for flushing, itching, tingling, and warmth were all significantly reduced by both aspirin regimens (p < .05 in all cases), although there were no significant differences between the 325-mg and 650-mg doses. The results were similar for each scoring method.

CONCLUSIONS

An aspirin regimen of 325 mg is effective in suppressing niacin-induced cutaneous reactions. Increasing the dose to 650 mg does not provide additional benefit.

Aging and atherosclerosis in human and nonhuman primates

Atherosclerosis is a major age-related process and public health problem and its clinical manifestations (coronary heart disease [CHD] and cerebrovascular disease) continue to be responsible for approximately 50% of all deaths occurring annually. In addition, CHD is responsible for over 70 to 80% of deaths among men and women over 65 years old. As our population ages (35 million people over the age of 65 in the U.S. by the year 2030) and because of the increased morbidity and mortality associated with atherosclerosis, an understanding of the role of aging in the development of atherosclerosis is needed. Multiple risk factors such as smoking, gender, hypertension, and lipids contribute to the development of atherosclerosis. However, these risk factors in combination explain only about half of the individual variability in incidence of CHD, and it has been hypothesized that age-related conditions may play a role. To propectively evaluate the effects of age per se on atherosclerosis progression in humans would require observation over many years. Thus, animal models that are representative of both aging processes and atherosclerosis would be extremely valuable. As such, nonhuman primates have been used extensively in atherosclerosis research. However, studies that will specifically evaluate the role of aging per se in contributing to development of atherosclerosis in nonhuman primates have only recently been initiated. In this review, the contribution of nonhuman primates to atherosclerosis research will be discussed, as will the development of atherosclerosis in both human and nonhuman primates. In addition, a role for age-related conditions in atherosclerosis development in both human and nonhuman primates will be outlined.

Potential role of viruses in neurodegeneration

Viruses have the capacity to induce alterations and degenerations of neurons by different direct and indirect mechanisms. In the review, we have focused on some examples that may provide new avenues for treatment or altering the course of infections, i.e., antibodies to fusogenic virus membrane proteins, drugs that interfere with lipid metabolism, calcium channel blockers, immunoregulatory molecules, and, and inhibitors of excitotoxic amino acids. Owing to their selectivity in attack on regions of nervous tissue, governed by viral factors and by routes of invasion, viral receptors or metabolic machineries of infected cells, certain viral infections show similarities in distribution of their resulting lesions in the nervous system to that of the common human neurodegenerative diseases (namely, motor neurons disease, Parkinson's disease, and Alzheimer's disease). However, it should be emphasized that no infectious agent has as yet provided a complete animal model for any of these diseases, nor has any infectious agent been linked to them from observations on clinical or postmortem materials.

Knowledge and Attitudes of Physicians about Lipids

A sample of 323 physicians from Edmonton, Alberta, was surveyed to evaluate their attitudes and knowledge level concerning heart disease and lipids. Of the sample, 117 physicians returned the questionnaire. When asked to choose significant risk factors of cardiovascular disease, 69% of the physicians indicated hypertension; 85% indicated smoking; and 87% indicated elevated serum cholesterol. Concerning the minimal low-density lipoprotein level that warrants treatment, 82% of the general practitioners and 50% of the specialists indicated that 4.2 mmol/L was the minimal level. This is in contrast to the level of 3.4 mmol/L for low-density lipoprotein recommended by the Canadian Consensus Conference on Cholesterol as the level at which treatment should be initiated.

FASTING PLASMA LIPID, GLUCOSE, AND INSULIN LEVELS IN PRADER-WILLI SYNDROME AND OBESE INDIVIDUALS

Plasma lipid, glucose, and insulin levels were measured from 26 patients with Prader-Willi syndrome (16 with the chromosome 15q deletion and 10 with normal chromosomes) and 32 obese, normal individuals. The average percentage of ideal body weight (IBW) for the former group was 175.6 ± 68.0, compared to 150.3 ± 43.8 for the latter. Fasting plasma lipid, glucose, and insulin levels were not significantly different between the two groups. No significant correlations were found among the three measurements in patients with PWS (deletion or nondeletion) or obese individuals and either age or percentage of IBW. Both insulin and glucose levels were higher in the PWS group, while only insulin levels were higher in the obese group compared with normative laboratory standards. Our study supports previously reported lipid, glucose, and insulin data in PWS and obesity.

Serum lipid distributions in canadian indians of northwestern ontario

Native Indians in the Sioux Lookout Zone of Northwestern Ontario experience lower mortality from cardiovascular diseases than does the general Canadian population, despite a higher prevalence of such risk factors as smoking, obesity, and hypertension. To investigate whether this pattern may be related to the population distribution of serum lipids, the authors conducted a cross-sectional survey. One hundred and ninety-three registered Indians, 18 years of age or older, living in four isolated villages in the Zone were interviewed and examined. Age, sex, height, and weight were determined. A blood specimen was analysed for fasting serum triglyceride, cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol. In relation to reference populations, the distribution of serum triglyceride, cholesterol, and LDL cholesterol values is similar to that reported in other Native and non-Native populations, while that of HDL cholesterol is higher. Elevated levels of HDL cholesterol in this population may play a role in protecting it from a higher incidence of coronary heart disease.

A long-term double-blind comparison of doxazosin and atenolol in patients with mild to moderate essential hypertension

The efficacy and safety of doxazosin and atenolol were compared following once-daily administration for up to 1 year, with a minimum of 20 weeks' active treatment. According to response, patients received doxazosin 1-16 mg day-1 or atenolol 50-100 mg day-1. Mean daily doses at the final efficacy assessment (between 20 weeks and 1 year) were doxazosin 11.8 mg and atenolol 94.2 mg. Atenolol produced somewhat greater falls in blood pressure than doxazosin. The differences were statistically significant in the supine but not in the standing position. A small mean reduction in heart rate was produced by doxazosin whereas atenolol produced a marked bradycardia. Analysis of the same patient group at 20 weeks revealed similar overall profiles of activity except that atenolol produced greater falls in blood pressure than in the longer term analysis. Serum concentrations of HDL/total cholesterol ratio were raised in the doxazosin treatment group and lowered in the atenolol group. Triglyceride concentrations fell in the doxazosin group and rose in the atenolol group. Significant differences (P less than 0.001) were observed between treatment groups for these parameters, all differences being in favour of doxazosin. Pharmacokinetics of doxazosin, measured at steady state in 36 patients, showed dose-related plasma concentrations, a mean half-life of about 12 h and relatively low intersubject variation. The incidence of side-effects was slightly greater for patients in the doxazosin group. Drug-related side-effects were mostly mild to moderate in severity with no serious drug-related occurrences in either treatment group. No serious drug-related abnormalities in laboratory biochemistry and haematology tests were observed in either treatment group.

The antihypertensive effects of doxazosin: a clinical overview

Doxazosin is a long-acting selective alpha 1-adrenoceptor antagonist which has been shown to be effective and well tolerated in the treatment of hypertension given in once-daily doses as monotherapy for up to 1 year or as an adjunct to thiazide or beta-adrenoceptor blockers. Doxazosin has a pharmacokinetic profile in both young adult and elderly subjects which is compatible with once-daily administration. This has been confirmed by measurement of steady state pharmacokinetics in patients receiving long-term doxazosin therapy. In controlled double-blind studies involving approximately 550 patients on doxazosin 1-16 mg once daily, significant reductions in both standing and supine BP were maintained throughout the 24 h dosing interval. Effectiveness of doxazosin in terms of BP lowering and proportion of responders was similar to that achieved with hydrochlorothiazide 25-100 mg once daily, atenolol 50-100 mg once daily, nadolol 40-160 mg once daily, metoprolol 100-200 mg per day given twice daily, or prazosin 1-20 mg per day given twice daily. Doxazosin was as effective in elderly patients as in the younger age group and was as effective in blacks as in caucasians. Doxazosin was well tolerated. Side-effects were generally mild to moderate in severity. Overall incidence, including postural effects early in treatment, was similar to that seen with the comparative agents. In comparison with placebo, doxazosin favourably increased (P less than 0.05) the HDL/total cholesterol ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Multicentre 12-week double-blind comparison of doxazosin, prazosin and placebo in patients with mild to moderate essential hypertension

A 12-week double-blind study was performed to compare the safety and efficacy of doxazosin, prazosin and placebo in 172 patients with essential hypertension. According to response, patients received doxazosin 1-16 mg once daily, prazosin 0.5-10 mg twice daily, or placebo. Mean final daily doses were doxazosin 11.3 mg and prazosin 13.8 mg. Doxazosin once daily and prazosin twice daily both produced statistically significant reductions in both standing and supine blood pressures when compared with placebo. No significant differences between treatments were recorded for standing and supine heart rates. Doxazosin, prazosin and placebo all had a similar effect on plasma lipid profiles, i.e. an increase in HDL/total cholesterol of approximately 10%. The differences between treatments were not statistically significant. The HDL/total cholesterol ratio significantly increased from baseline to the end of treatment for all three groups, the decrease in triglycerides being statistically significant only in the doxazosin-treated group.

Lipid screening in family practice: a critical appraisal of recent evidence

Applying principles of critical appraisal to evidence for lipid screening in family practice, one concludes that elevations of triglyceride are not a defined risk for coronary heart disease at present and screening cannot be justified. In contrast, there is now good evidence that elevated cholesterol is not only a primary risk factor for, but also a cause of coronary heart disease. There has been no randomized trial of cholesterol screening to date, leaving the physician in the position of knowing something should be done about the problem, but the best methods are yet to be clarified.

Diacyl, Alkylacyl, and Alkenylacyl Phospholipids of Meloidogyne javanica Females

The phospholipid composition and acyl, alkyl, and alkenyl group compositions of diacyl, alkylacyl, and alkenylacyl phosphoglycerides of M. javanica were investigated. Phospholipid was comprised of 61.7% choline phosphoglyceride, 22.0% ethanolamine phosphoglyceride, and smaller quantities of six other lipids. Phospholipid fatty acid was more unsaturated than neutral lipid fatty acid and contained 61.3% octadecenoic (18:1) acid. Fatty acid at the 1-position of diacyl phospholipids was shorter and more saturated than that at the 2-position. Compared to choline phosphoglyceride, ethanolantine phosphoglyceride contained less 18:1 and 20:5 and more 18:0 and 20:0 acid. Alkenylacyl and alkylacyl compounds comprised 34.6% and 9.3%, respectively, of the ethanolamine phosphoglyceride but only 0.5% and 0.6% of the choline phosphoglyceride. Alkenylacyl and alkylacyl ethanolamine phosphoglycerides contained a smaller percentage of 20-carbon polyunsaturated acid at their 2-positions than did their diacyl analogue. At least 95% of the alkenyl and alkyl groups were 18:0 compounds. Tomato roots did not contain alkenylacyl or alkylacyl phosphoglycerides; their occurrence in M. javanica is a significant biochemical difference between the nematode and its host.

The Sterol, Fatty Acid, and Hydrocarbon Composition of Globodera solanacearum

Globodera solanacearum females were found to have less than 0.01% of dry wt as sterols. Seven sterols were detected in the nematode, with stanols (campestanol and stigmastanol) making tip more than 50% of the total sterols present. Lipid amounted to 29.4% of the dry weight of the nematode. Triglyceride, free fatty acid, and phospholipid classes were composed predominantly of 20:4, 20:1, and 18:1 fatty acids. Of the total weight of fatty acids found in G. solanacearum females, the greatest portion occurred in the triglyceride fraction, followed by the free fatty acid fraction then the phospholipid fraction. Several unidentified hydrocarbons were detected in the nematode. Paraffinic hydrocarbons detected ranged in carbon length from C15 to C29. Total concentration of hydrocarbon composed 0.20% of the dry wt.

Effect of insulin on sterol and fatty acid synthesis and hydroxymethylglutaryl CoA reductase activity in mammalian cells grown in culture

The effects of insulin on the synthesis of sterols and fatty acids and on the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.34), a rate-limiting enzyme for sterol synthesis, were studied in mammalian cells grown in culture. While in some established cell lines sterol synthesis was not affected significantly by the hormone, in the nonpermanent human and animal cells the synthesis of lipids, especially that of sterols, as well as the activity of the reductase were stimulated following an incubation with insulin in a medium containing serum albumin for a few hours or longer. These effects of insulin were also demonstrable in the presence of solvent-extracted serum, which itself increases sterol synthesis and reductase activity. In medium containing whole serum insulin was ineffective. Addition of glucose decreased sterol synthesis as well as reductase activity. The effects of insulin were prevented by cycloheximide and are probably due to an increased synthesis of 3-hydroxy-3-methylglutaryl CoA reductase or of a protein that regulates its activity.

Temperature-sensitive mutants of Escherichia coli requiring saturated and unsaturated fatty acids for growth: isolation and properties

A procedure is described for selection of temperature-sensitive mutants affecting fatty-acid synthesis based upon radiation suicide of wild-type organisms by tritiated acetate selectively incorporated into fatty acids. At 37 degrees , two of the mutants extensively incorporate fatty-acid supplements provided in the medium, and grow for extended periods only when a trans-unsaturated or a combination of saturated and cis-unsaturated fatty acids is available. In vivo fatty-acid synthesis, measured by [(14)C]acetate incorporation, is temperature-sensitive in these strains relative to protein synthesis and other non-lipid macromolecular syntheses using acetate. The biochemical nature of these mutations has not been identified.

Rapid lateral diffusion of phospholipids in rabbit sarcoplasmic reticulum

Phospholipid spin labels incorporated in the sarcoplasmic reticulum from rabbit-skeletal muscle undergo rapid lateral diffusion within the plane of the membrane. The diffusion constant, D, is 6x10(-8) cm(2)/sec at 37 degrees . With this diffusion constant, a phospholipid molecule can diffuse a distance of the order of 5000 nm in 1 sec.