Cholestanol: A serum marker to guide LDL cholesterol-lowering therapy

Statins have been the mainstay of lipid-lowering therapy since their introduction. However, as lower LDL cholesterol targets are sought, adjunct therapies are becoming increasingly important. Few patients reach new targets with statin monotherapy. We propose that the cholestanol: cholesterol ratio can be used to guide lipid-lowering therapy and result in greater numbers of patients reaching target LDL cholesterol. By determining whether a patient is mainly a synthesizer or absorber of cholesterol, customized regimens can be used and are expected to improve patient outcomes and minimize costs of treatment. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Dizziness after traumatic brain injury: Overview and measurement in the clinical setting

Traumatic brain injury (TBI) may result in a variety of cognitive, behavioural and physical impairments. Dizziness has been reported in up to 80% of cases within the first few days after injury. The literature was reviewed to attempt to delineate prevalence of dizziness as a symptom, impairments causing dizziness, the functional limitations it causes and its measurement. The literature provides widely differing estimates of prevalence and vestibular system dysfunction appears to be the best reported of impairments contributing to this symptom. The variety of results is discussed and other possible causes for dizziness were reviewed. Functional difficulties caused by dizziness were not reported for this population in the literature and review of cognitive impairments suggests that existing measurement tools for dizziness may be problematic in this population. Research on the functional impact of dizziness in the TBI population and measurement of these symptoms appears to be warranted.

Ocular toxicity of intravitreous adalimumab (Humira) in the rabbit

Purpose To evaluate the ocular toxicity of escalating doses of intravitreous adalimumab (Humira) in the rabbit eye. Methods Twelve New Zealand albino rabbits received unilateral intravitreous injections of 0.1 ml of adalimumab 0.25 mg (three eyes), 0.50 mg (three eyes), 1.0 mg (three eyes) or 0.1 ml balanced salt solution (BSS, threeeyes). Slit-lamp biomicroscopy and fundoscopy were carried out at baseline, day 1, 7 and 14 following intravitreous injection, while electroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14, and histopathological examination of the eyes was performed. Results Slit-lamp biomicroscopy and fundoscopy were normal in eyes having received BSS, 0.25 mg or 0.50 mg adalimumab; however, inflammation was present in two of three eyes having received 1.0 mg adalimumab. Similarly, comparison of scotopic and photopic ERG light at baseline and day 14 demonstrated no changes in eyes receiving BSS, 0.25 mg or 0.50 mg adalimumab, but two of three eyes having received 1.0 mg adalimumab showed a greater than 30% reduction in a and b wave. Finally, histopathology demonstrated no differences between eyes receiving BSS, 0.25 mg or 0.50 mg of adalimumab, but two of three eyes injected with 1.0 mg demonstrated inflammatory cell infiltration of the vitreous and anterior chamber, with one of these eyes demonstrating retinal necrosis. Conclusions Escalating doses of intravitreous adalimumab in rabbit eyes caused no detectable functional or structural ocular toxicity up to a dose of 0.50 mg. Administration of 1.0 mg in 0.1 ml was associated with an inflammatory reaction and retinal necrosis.

Application of biotechnology in breeding lentil for resistance to biotic and abiotic stress

Lentil is a self-pollinating diploid (2n = 14 chromosomes) annual cool season legume crop that is produced throughout the world and is highly valued as a high protein food. Several abiotic stresses are important to lentil yields world wide and include drought, heat, salt susceptibility and iron deficiency. The biotic stresses are numerous and include: susceptibility to Ascochyta blight, caused by Ascochyta lentis; Anthracnose, caused by Colletotrichum truncatum; Fusarium wilt, caused by Fusarium oxysporum; Sclerotinia white mold, caused by Sclerotinia sclerotiorum; rust, caused by Uromyces fabae; and numerous aphid transmitted viruses. Lentil is also highly susceptible to several species of Orabanche prevalent in the Mediterranean region, for which there does not appear to be much resistance in the germplasm. Plant breeders and geneticists have addressed these stresses by identifying resistant/tolerant germplasm, determining the genetics involved and the genetic map positions of the resistant genes. To this end progress has been made in mapping the lentil genome and several genetic maps are available that eventually will lead to the development of a consensus map for lentil. Marker density has been limited in the published genetic maps and there is a distinct lack of co-dominant markers that would facilitate comparisons of the available genetic maps and efficient identification of markers closely linked to genes of interest. Molecular breeding of lentil for disease resistance genes using marker assisted selection, particularly for resistance to Ascochyta blight and Anthracnose, is underway in Australia and Canada and promising results have been obtained. Comparative genomics and synteny analyses with closely related legumes promises to further advance the knowledge of the lentil genome and provide lentil breeders with additional genes and selectable markers for use in marker assisted selection. Genomic tools such as macro and micro arrays, reverse genetics and genetic transformation are emerging technologies that may eventually be available for use in lentil crop improvement.

Tidal influence on behaviour of a coastal aquifer adjacent to a low-relief estuary

The tidal influence on groundwater hydrodynamics, salt-water intrusion and submarine groundwater discharge from coastal/estuarine aquifers is poorly quantified for systems with a mildly sloping beach, in contrast to the case where a vertical beach face is assumed. We investigated the effect of beach slope for a coastal aquifer adjacent to a low-relief estuary, where industrial waste was emplaced over the aquifer. The waste was suspected to discharge leachate towards the estuary. Field observations at various locations showed that tidally induced groundwater head fluctuations were skewed temporally. Frequency analysis suggested that the fluctuation amplitudes decreased exponentially and the phase-tags increased Linearly for the primary tidal signals as they propagated inland. Salinisation zones were observed in the bottom part of the estuary and near the beach surface. Flow and transport processes in a cross-section perpendicular to the estuary were simulated using SEAWAT-2000, which is capable of depicting density-dependent flow and multi-species transport. The simulations showed that the modelled water table fluctuations were in good agreement with the monitored data. Further simulations were conducted to gain insight into the effects of beach slope. In particular the limiting case of a vertical beach face was considered. The simulations showed that density difference and tidal forcing drive a more complex hydrodynamic pattern for the mildly sloping beach than the vertical beach, as well as a profound asymmetry in tidally induced water table fluctuations and enhanced salt-water intrusion. The simulation results also indicated that contaminant transport from the aquifer to the estuary was affected by the tide, where for the mildly sloping beach, the tide tended to intensify the vertical mass exchange in the vicinity of the shorelines, (c) 2005 Elsevier B.V. All rights reserved.

Effect of the immunosuppressants on hepatocyte cells proliferation and apoptosis during liver regeneration after hepatectomy - molecular studies

The regeneration and remodeling of the transplanted liver is the result of hepatocyte proliferation and apoptosis (programmed cell death). The purpose of this study was to verify the influence of immunosuppressants on the expression levels of genes: IL-6 (regulator of hepatocyte proliferation), pro-apoptotic (Bak and Bax) and anti-apoptotic (Bcl-Xl and Bcl-2). 36 newborn suckling rats (age 5-7 days, weight 6-10 g) were divided into four groups: hepatectomy, hepatectomy plus methylprednisolone, hepatectomy plus CsA and hepatectomy plus Tac. The same experiments were performed in 24 weaning rats (age 21-23 days, weight 30-50 g). The animals were killed one day after the hepatectomy and the remnant livers were analyzed. The livers of all animals exhibited histological changes of liver regeneration. The immunosuppressants did not promote any alteration on IL-6 gene expression levels. Methylprednisolone and CsA increased the expression levels of Bak gene in newborn rats. However, methylprednisolone and Tac promoted increased expression levels of Bcl-2 in all groups. We hypothesize that these effects explain the efficacy of these drugs on the treatment of acute and chronic liver rejection as the expression of Bcl-2 in cholangiocytes is decreased as a consequence of bile duct lesions.

Mechanism of ribonuclease inhibition by ribonuclease inhibitor protein based on the crystal structure of its complex with ribonuclease A

We describe the mechanism of ribonuclease inhibition by ribonuclease inhibitor, a protein built of leucine-rich repeats, based on the crystal structure of the complex between the inhibitor and ribonuclease A. The structure was determined by molecular replacement and refined to an R(cryst) of 19.4% at 2.5 Angstrom resolution. Ribonuclease A binds to the concave region of the inhibitor protein comprising its parallel beta-sheet and loops. The inhibitor covers the ribonuclease active site and directly contacts several active-site residues. The inhibitor only partially mimics the RNase-nucleotide interaction and does not utilize the pi phosphate-binding pocket of ribonuclease A, where a sulfate ion remains bound. The 2550 Angstrom(2) of accessible surface area buried upon complex formation may be one of the major contributors to the extremely tight association (K-i = 5.9 x 10(-14) M). The interaction is predominantly electrostatic; there is a high chemical complementarity with 18 putative hydrogen bonds and salt links, but the shape complementarity is lower than in most other protein-protein complexes. Ribonuclease inhibitor changes its conformation upon complex formation; the conformational change is unusual in that it is a plastic reorganization of the entire structure without any obvious hinge and reflects the conformational flexibility of the structure of the inhibitor. There is a good agreement between the crystal structure and other biochemical studies of the interaction. The structure suggests that the conformational flexibility of RI and an unusually large contact area that compensates for a lower degree of complementarity may be the principal reasons for the ability of RI to potently inhibit diverse ribonucleases. However, the inhibition is lost with amphibian ribonucleases that have substituted most residues corresponding to inhibitor-binding residues in RNase A, and with bovine seminal ribonuclease that prevents inhibitor binding by forming a dimer. (C) 1996 Academic Press Limited

Immunohistochemical detection of polyductin and co-localization with liver progenitor cell markers during normal and abnormal development of the intrahepatic biliary system and in adult hepatobiliary carcinomas

The longest open reading frame of PKHD1 (polycystic kidney and hepatic disease 1), the autosomal recessive polycystic kidney disease (ARPKD) gene, encodes a single-pass, integral membrane protein named polyductin or fibrocystin. A fusion protein comprising its intracellular C-terminus, FP2, was previously used to raise a polyclonal antiserum shown to detect polyductin in several human tissues, including liver. In the current study, we aimed to investigate by immunohistochemistry the detailed polyductin localization pattern in normal (ductal plate [DP], remodelling ductal plate [RDP], remodelled bile ducts) and abnormal development of the primitive intrahepatic biliary system, known as ductal plate malformation (DPM). This work also included the characterization of polyductin expression profile in various histological forms of neonatal and infantile cholestasis, and in cholangiocellular carcinoma (CCC) and hepatocellular carcinoma (HCC). We detected polyductin expression in the intrahepatic biliary system during the DP and the RDP stages as well as in DPM. No specific staining was found at the stage of remodelled bile ducts. Polyductin was also detected in liver biopsies with neonatal cholestasis, including mainly biliary atresia and neonatal hepatitis with ductular reaction as well as congenital hepatic fibrosis. In addition, polyductin was present in CCC, whereas it was absent in HCC. Polyductin was also co-localized in some DP cells together with oval stem cell markers. These results represent the first systematic study of polyductin expression in human pathologies associated with abnormal development of intrahepatic biliary tree, and support the following conclusions: (i) polyductin expression mirrors developmental properties of the primitive intrahepatic biliary system; (ii) polyductin is re-expressed in pathological conditions associated with DPM and (iii) polyductin might be a potential marker to distinguish CCC from HCC.

Thyroid and the environment: exposure to excessive nutritional iodine increases the prevalence of thyroid disorders in Sao Paulo, Brazil

Objective: To evaluate the prevalence of chronic autoimmune thyroiditis (CAT) and iodine-induced hypothyroidism, hyperthyroidism (overt and subclinical). and goiter in a population exposed to excessive iodine intake for 5 years (table salt iodine concentrations: 40-100 mg/kg salt). Design: This was a population-based, cross-sectional study with 1085 participants randomly selected from a metropolitan area in Sao Paulo, Brazil, and conducted during the first semester of 2004. Methods: Thyroid ultrasound examination was performed in all participants and samples of urine and blood were collected from each subject. Serum levels of thyroid-stimulating hormone, free thyroxine, and anti-thyroid peroxidase (TPO) antibodies, urinary iodine concentration. thyroid volume, and thyroid echogenicity were evaluated. We also analyzed table salt iodine concentrations. Results: At the time the study was conducted, table salt iodine concentrations were within the new official limits (20-60 mg/kg salt). Nevertheless, in 45.6%, of the participants, urinary iodine excretion was excessive (above 300 mu g/l) and, in 14.1%, it was higher than 400 mu g/l. The prevalence of CAT (including atrophic thyroiditis) was 16.9% (183/1085), women were more affected than men (21.5 vs 9.1% respectively, P=0.02). Hypothyroidism was detected in 8.0%, (87/1085) of the Population with CAT. Hyperthyroidism was diagnosed in 3.3% of the individuals (36/1085) and goiter was identified in 3.1% (34/1085). Conclusions: Five years of excessive iodine intake by the Brazilian population may have increased the prevalence of CAT and hypothyroidism in subjects genetically predisposed to thyroid autoimmune diseases. Appropriate screening for early detection of thyroid dysfunction may be considered during excessive nutritional iodine intake.

Biliary and pancreatic dysgenesis in mice harboring a mutation in Pkhd1

Autosomal recessive polycystic kidney disease is a hereditary fibrocystic disease that involves the kidneys and the biliary tract. Mutations in the PKHD1 gene are responsible for typical forms of autosomal recessive polycystic kidney disease. We have generated a mouse model with targeted mutation of Pkbd1 by disrupting exon 4, resulting in a mutant transcript with deletion of 66 codons and expression at similar to 30% of wild-type levels. Pkhd1(del4/d3l4) mice develop intrahepatic bile duct proliferation with progressive cyst formation and associated periportal fibrosis. In addition, these mice exhibit extrahepatic manifestations, including pancreatic cysts, splenomegaly, and common bile duct dilation. The kidneys are unaffected both histologically and functionally. Fibrocystin is expressed in the apical membranes and cilia of bile ducts and distal nephron segments but is absent from the proximal tubule. This pattern is unchanged in orthologous models of autosomal dominant polycystic kidney disease due to mutation in Pkd1 or Pkd2. Mutant fibrocystin in Pkhd1(del4/d3l4) mice also retains this expression pattern. The hypomorphic Pkhd1(del4/d3l4) mouse model provides evidence that reduced functional levels of fibrocystin are sufficient for cystogenesis and fibrosis in the liver and pancreas, but not the kidney, and supports the hypothesis of species-dependent differences in susceptibility of tissues to Pkbdl mutations.

Metabolic activation of aromatic amines by human pancreas

Epidemiologic studies have suggested that aromatic amines (and nitroaromatic hydrocarbons) may be carcinogenic for human pancreas, Pancreatic tissues from 29 organ donors (13 smokers, 16 non-smokers) were examined for their ability to metabolize aromatic amines and other carcinogens, Microsomes showed no activity for cytochrome P450 (P450) 1A2-dependent N-oxidation of 4-aminobiphenyl (ABP) or for the following activities (and associated P450s): aminopyrine N-demethylation and ethylmorphine N-demethylation (P450 3A4); ethoxyresorufin O-deethylation (P450 1A1) and pentoxyresorufin O-dealkylation (P450 2B6); p-nitrophenol hydroxylation and N-nitrosodimethylamine N-demethylation (P450 2E1); lauric acid omega-hydroxylation (P450 4A1); and 4-(methylnitrosamino)-1-(3-pyridyl-1-butanol) (NNAL) and 4-(methylnitrosamino)1-(3-pyridyl)-1-butanone (NNK) alpha-oxidation (P450 1A2, 2A6, 2D6). Antibodies were used to examine microsomal levels of P450 1A2, 2A6, 2C8/9/18/19, 2E1, 2D6, and 3A3/ 4/5/7 and epoxide hydrolase. Immunoblots detected only epoxide hydrolase at low levels; P450 levels were <1% of liver. Microsomal benzidine/prostaglandin hydroperoxidation activity was low. In pancreatic cytosols and microsomes, 4-nitrobiphenyl reductase activities were present at levels comparable to human liver. The O-acetyltransferase activity (AcCoA-dependent DNA-binding of [H-3]N-hydroxy-ABP) of pancreatic cytosols was high, about two-thirds the levels measured in human colon. Cytosols showed high activity for N-acetylation of p-aminobenzoic acid, but not of sulfamethazine, indicating that acetyltransferase-1 (NAT1) is predominantly expressed in this tissue. Cytosolic sulfotransferase was detected at low levels. Using P-32-post-labeling enhanced by butanol extraction, putative arylamine-DNA adducts were detected in most samples. Moreover, in eight of 29 DNA samples, a major adduct was observed that was chromatographically identical to the predominant ABP-DNA adduct, N-(deoxyguanosin-8-yl)-ABP. These results are consistent with a hypothesis that aromatic amines and nitroaromatic hydrocarbons may be involved in the etiology of human pancreatic cancer.

Studies on the gelation of photocatalysed dicyanate ester resins

The gel point of a dicyanate ester resin (Arocy B-10 (4-4'-dicyanato-2,2'-diphenylpropane)) heated following irradiation in the presence of the catalyst tricarbonyl cyclopentadienyl manganese (CpMn(CO)(3)) was studied using differential scanning calorimetry (d.s.c.) and dynamic rheological techniques over the temperature range 110-140 degrees C. The gel times of another commercial cyanate ester (RTX366) were also studied using independent rheological techniques, and the results agreed within experimental error. Gel times decreased linearly with increasing catalyst level and with increasing temperature according to an Arrhenius relation with activation energy of 68 +/- 6 kJmol(-1). The gel conversion was calculated by correlation of the rheological gel data to d.s.c. data to be 0.57 +/- 0.02, and differences between techniques, and between theoretical predictions, are discussed. Evidence is produced that the photocatalysed polymerization results in a greater rate of cyclotrimerization, less intramolecular cyclization and a more rigid network than the uncatalysed or metal salt-catalysed high-temperature polymerization. (C) 1997 Elsevier Science Ltd.

Age-dependent increase in blood pressure in two different Native American communities in Brazil

Objective Cardiovascular risk factors were surveyed in two Indian populations (Guarani, n=60; Tupinikin, n=496) and in a non-Indian group (n=114) living in the same reserve in southeast Brazilian coast. The relationship between an age-dependent blood pressure (BP) increase with salt consumption was also investigated. Methods Overnight (12 h) urine was collected to evaluate Na excretion. Fasting glucose and lipids, anthropometry, BP, ECG and carotid-femoral pulse wave velocity (PWV) were measured in a clinic visit. Participation (318 men/352 women, age 20-94 years; mean=37.6 +/- 14.9 years) comprised 80% of the eligible population. Results The prevalence of hypertension, diabetes and high cholesterol was similar in Tupinikins and in non-Indians and higher than in Guaranis. The prevalence of smoking and obesity was higher in the latter group. Hypertension and diabetes were detected in only one individual of the Guarani group. Mean BP adjusted to age and BMI was significantly lower (P<0.01) in Guaranis (82.8 +/- 1.6 mmHg) than in Tupinikins (92.3 +/- 0.5 mmHg) and non-Indians (91.6 +/- 1.1 mmHg). Urinary Na excretion (mEq/12h), however, was similar in the three groups (Guarani=94 +/- 40; Tupinikin=105 +/- 56; non-Indian=109 +/- 55; P>0.05). PWV (m/s) was lower (P<0.01) in Guarani (7.5 +/- 1.4) than in Tupinikins (8.8 +/- 2.2) and non-Indians (8.4 +/- 2.0). Multiple regression analysis showed that age and waist-to-hip ratio (WHR) were independent predictors of SBP and DBP (r(2)=0.44) in Tupinikins, whereas the WHR was the unique independent predictor of BP variability in Guaranis (r(2)=0.22). Conclusion Lower BP levels in Guaranis cannot be explained by low salt intake observed in other primitive populations. J Hypertens 27:1753-1760 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Congenic strains provide evidence that four mapped loci in chromosomes 2, 4, and 16 influence hypertension in the SHR

Aneas I, Rodrigues MV, Pauletti BA, Silva GJ, Carmona R, Cardoso L, Kwitek AE, Jacob HJ, Soler JM, Krieger JE. Congenic strains provide evidence that four mapped loci in chromosomes 2, 4, and 16 influence hypertension in the SHR. Physiol Genomics 37: 52-57, 2009. First published January 6, 2009; doi: 10.1152/physiolgenomics.90299.2008. - To dissect the genetic architecture controlling blood pressure (BP) regulation in the spontaneously hypertensive rat (SHR) we derived congenic rat strains for four previously mapped BP quantitative trait loci (QTLs) in chromosomes 2, 4, and 16. Target chromosomal regions from the Brown Norway rat (BN) averaging 13 - 29 cM were introgressed by marker-assisted breeding onto the SHR genome in 12 or 13 generations. Under normal salt intake, QTLs on chromosomes 2a, 2c, and 4 were associated with significant changes in systolic BP (13, 20, and 15 mmHg, respectively), whereas the QTL on chromosome 16 had no measurable effect. On high salt intake (1% NaCl in drinking water for 2 wk), the chromosome 16 QTL had a marked impact on SBP, as did the QTLs on chromosome 2a and 2c (18, 17, and 19 mmHg, respectively), but not the QTL on chromosome 4. Thus these four QTLs affected BP phenotypes differently: 1) in the presence of high salt intake (chromosome 16), 2) only associated with normal salt intake (chromosome 4), and 3) regardless of salt intake (chromosome 2c and 2a). Moreover, salt sensitivity was abrogated in congenics SHR. BN2a and SHR. BN16. Finally, we provide evidence for the influence of genetic background on the expression of the mapped QTLs individually or as a group. Collectively, these data reveal previously unsuspected nuances of the physiological roles of each of the four mapped BP QTLs in the SHR under basal and/or salt loading conditions unforeseen by the analysis of the F2 cross.

AT(1) receptor participates in the cardiac hypertrophy induced by resistance training in rats

Resistance training is accompanied by cardiac hypertrophy, but the role of the renin-angiotensin system (RAS) in this response is elusive. We evaluated this question in 36 male Wistar rats divided into six groups: control (n = 6); trained (n = 6); control + losartan (10 mg.kg(-1).day(-1), n = 6); trained + losartan (n = 6); control + high-salt diet (1%, n = 6); and trained + high-salt diet (1%, n = 6). High salt was used to inhibit the systemic RAS and losartan to block the AT(1) receptor. The exercise protocol consisted of: 4 x 12 bouts, 5x/wk during 8 wk, with 65-75% of one repetition maximum. Left ventricle weight-to-body weight ratio increased only in trained and trained + high-salt diet groups (8.5% and 10.6%, P < 0.05) compared with control. Also, none of the pathological cardiac hypertrophy markers, atrial natriuretic peptide, and alpha MHC (alpha-myosin heavy chain)-to-beta MHC ratio, were changed. ACE activity was analyzed by fluorometric assay (systemic and cardiac) and plasma renin activity (PRA) by RIA and remained unchanged upon resistance training, whereas PRA decreased significantly with the high-salt diet. Interestingly, using Western blot analysis and RT-PRC, no changes were observed in cardiac AT(2) receptor levels, whereas the AT(1) receptor gene (56%, P < 0.05) and protein (31%, P < 0.05) expressions were upregulated in the trained group. Also, cardiac ANG II concentration evaluated by ELISA remained unchanged (23.27 +/- 2.4 vs. 22.01 +/- 0.8 pg/mg, P > 0.05). Administration of a subhypotensive dose of losartan prevented left ventricle hypertrophy in response to the resistance training. Altogether, we provide evidence that resistance training-induced cardiac hypertrophy is accompanied by induction of AT(1) receptor expression with no changes in cardiac ANG II, which suggests a local activation of the RAS consistent with the hypertrophic response.