Quantitative trait locus mapping and functional genomics of an organophosphate resistance trait in the western corn rootworm, Diabrotica virgifera virgifera

The western corn rootworm, Diabrotica virgifera virgifera, is an insect pest of corn and population suppression with chemical insecticides is an important management tool. Traits conferring organophosphate insecticide resistance have increased in frequency amongst D. v. virgifera populations, resulting in the reduced efficacy in many corn-growing regions of the USA. We used comparative functional genomic and quantitative trait locus (QTL) mapping approaches to investigate the genetic basis of D. v. virgifera resistance to the organophosphate methyl-parathion. RNA from adult methyl-parathion resistant and susceptible adults was hybridized to 8331 microarray probes. The results predicted that 11 transcripts were significantly up-regulated in resistant phenotypes, with the most significant (fold increases ≥ 2.43) being an α-esterase-like transcript. Differential expression was validated only for the α-esterase (ST020027A20C03), with 11- to 13-fold greater expression in methyl-parathion resistant adults (P < 0.05). Progeny with a segregating methyl-parathion resistance trait were obtained from a reciprocal backcross design. QTL analyses of high-throughput single nucleotide polymorphism genotype data predicted involvement of a single genome interval. These data suggest that a specific carboyxesterase may function in field-evolved corn rootworm resistance to organophosphates, even though direct linkage between the QTL and this locus could not be established.

Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment

Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.

Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background

We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

Stratified dispersal and increasing genetic variation during the invasion of Central Europe by the western corn rootworm, Diabrotica virgifera virgifera

Invasive species provide opportunities for investigating evolutionary aspects of colonization processes, including initial foundations of populations and geographic expansion. Using microsatellite markers and historical information, we characterized the genetic patterns of the invasion of the western corn rootworm (WCR), a pest of corn crops, in its largest area of expansion in Europe: Central and South-Eastern (CSE) Europe. We found that the invaded area probably corresponds to a single expanding population resulting from a single introduction of WCR and that gene flow is geographically limited within the population. In contrast to what is expected in classical colonization processes, an increase in genetic variation was observed from the center to the edge of the outbreak. Control measures against WCR at the center of the outbreak may have decreased effective population size in this area which could explain this observed pattern of genetic variation. We also found that small remote outbreaks in southern Germany and north-eastern Italy most likely originated from long-distance dispersal events from CSE Europe. We conclude that the large European outbreak is expanding by stratified dispersal, involving both continuous diffusion and discontinuous long-distance dispersal. This latter mode of dispersal may accelerate the expansion of WCR in Europe in the future.

Absence of genetic divergence between western corn rootworms (Coleoptera: Chrysomelidae) resistant and susceptible to control by crop rotation

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of corn, Zea mays L., in North America that has recently invaded Europe. A loss of ovipositional fidelity to cornfields has allowed the species to circumvent crop rotation as a means of control in part of its range in the United States. Analyses of variation at eight microsatellite loci provided no evidence for general genetic differentiation between samples of western corn rootworm collected in soybean, Glycine max (L.) Merr., fields and those collected in cornfields both inside and outside the rotation-resistance problem area. This result suggests that few or no barriers to gene flow exist between rotation-resistant and -susceptible rootworm populations. The implications of this result for the management of western corn rootworm in North America and Europe are discussed.

Host-associated populations in the lettuce root aphid, Pemphigus bursarius (L.)

Pemphigus bursarius is a host-alternating aphid in which annual rounds of sexual reproduction on its primary host, Populus nigra, are interspersed with parthenogenesis on a range of secondary hosts. Evidence was sought for the existence of genetically distinct populations, associated with different secondary hosts, in P. bursarius. Microsatellite markers revealed that genetically distinct populations were present on three different secondary host species. Microsatellites were also used, in conjunction with mitochondrial DNA sequence variation, to investigate the relationships between aphids on Populus, following sexual reproduction, and those on the secondary hosts. Evidence was found for a distinct, cyclically parthenogenetic population that exploited Lactuca sativa as its secondary host. In contrast, populations associated with Matricaria inodora appeared to be largely composed of obligate parthenogens or may even have been another species of Pemphigus. Populations on Lapsana communis appeared to be a mixture of cyclical and obligate parthenogens and were more genetically heterogeneous than those on other secondary hosts, possibly due to founder effects. Experiments to measure the performance of P. bursarius clones on different secondary hosts were inconclusive, failing to demonstrate either the presence or absence of adaptations to secondary hosts.

The Molecular Epidemiology of Streptococcus pneumoniae with Quinolone Resistance Mutations

BACKGROUND

The purpose of this study was to determine the prevalence of fluoroquinolone resistance and quinolone resistance-determining region (QRDR) mutations among Streptococcus pneumoniae isolates in the United States during the period of 2001-2002. A second objective was to examine the genetic relatedness of pneumococcal isolates with parC and/or gyrA mutations during the period of 1994-2002.

METHODS

Susceptibility testing was performed for 1902 S. pneumoniae isolates collected in the United States during the period of 2001-2002. On the basis of the minimum inhibitory concentration (MIC) of ciprofloxacin, 146 isolates were selected from the 2001-2002 study for QRDR analysis of parC, parE, gyrA, and gyrB genes. The genetic relatedness of isolates with parC and/or gyrA mutations from 2001-2002 (n=55) and from 3 US surveillance studies conducted during 1994-2000 (n=56) was determined by pulsed-field gel electrophoresis (PFGE).

RESULTS

Between 1999-2000 and 2001-2002, there was a 2-fold increase in the rate of ciprofloxacin resistance (MIC, >or=4 micro g/mL), from 1.2% to 2.7%, and in the rate of levofloxacin nonsusceptibility (MIC, >or=4 micro g/mL), from 0.6% to 1.3%. The 111 isolates with parC and/or gyrA mutations were assigned to 48 different PFGE types. Forty-four isolates (40%) belonged to 8 PFGE types that were closely related to widespread clones. Fifteen of the 43 levofloxacin-nonsusceptible pneumococci (LNSP) belonged to 4 PFGE types that were closely related to major clones (Spain(23F)-1 [n=6]; Spain(6B)-2 [n=5], Taiwan(19F)-14 [n=2], and Tennessee(23F)-4 [n=2]).

CONCLUSION

The population of fluoroquinolone-resistant S. pneumoniae in the United States has increased but remains genetically diverse. However, 35% of LNSP were related to widespread pneumococcal clones, increasing the potential for the rapid spread of quinolone resistance in this species.

Population genetic structure of the lettuce root aphid, Pemphigus bursarius (L.), in relation to geographic distance, gene flow and host plant usage

Microsatellite markers were used to examine the population structure of Pemphigus bursarius, a cyclically parthenogenetic aphid. Substantial allele frequency differences were observed between populations on the primary host plant (collected shortly after sexual reproduction) separated by distances as low as 14 km. This suggested that migratory movements occur over relatively short distances in this species. However, the degree of allele frequency divergence between populations was not correlated with their geographical separation, indicating that isolation by distance was not the sole cause of spatial genetic structuring. Significant excesses of homozygotes were observed in several populations. Substantial allele frequency differences were also found between aphids on the primary host and those sampled from a secondary host plant after several parthenogenetic generations at the same location in two successive years. This could have been due to the existence of obligately parthenogenetic lineages living on the secondary host or genetically divergent populations confined to different secondary host plant species but sharing a common primary host.

Postnatal development and control of the pulmonary surfactant system in the tammar wallaby Macropus eugenii

Marsupials are born at an early stage of development and are adapted for future development inside the pouch. Whether the pulmonary surfactant system is fully established at this altricial stage is unknown. This study correlates the presence of surfactant proteins (SP-A, SP-B and SP-D), using immunohistochemistry, with the ex-utero development of the lung in the tammar wallaby Macropus eugenii and also investigates the control of phosphatidylcholine (PC) secretion from developing alveolar type II cells. All three surfactant proteins were found at the site of gas exchange in the lungs of joeys at all ages, even at birth when the lungs are in the early stages of the terminal air-sac phase. Co-cultures of alveolar type II cells and fibroblasts were isolated from the lungs of 30- and 70-day-old joeys and incubated with the hormones dexamethasone (10 μmol l–1), prolactin (1 μmol l–1) or triiodothyronine (100 μmol l–1) or with the autonomic secretagogues isoproterenol (100 μmol l–1) or carbamylcholine chloride (100 μmol l–1). Basal secretion of PC was greater at 30 days of age than at 70 days. Co-cultures responded to all five agonists at 30 days of age, but only the autonomic secretagogues caused a significant increase in PC secretion at 70 days of age. This demonstrates that, as the cells mature, their activity and responsiveness are reduced. The presence of the surfactant proteins at the site of gas exchange at birth suggests that the system is fully functional. It appears that surfactant development is coupled with the terminal air-sac phase of lung development rather than with birth, the length of gestation or the onset of air-breathing.

Complement-mediated killing of Borrelia burgdorferi by nonimmune sera from sika deer

Various species of cervid deer are the preferred hosts for adult, black-legged ticks (Ixodes scapularis and Ixodes pacificus) in the United States. Although frequently exposed to the agent of Lyme disease (Borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. We examined the borreliacidal activity of normal and B. burgdorferi-immune sera from sika deer (Cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from reservoir-competent mice and rabbits. All normal deer sera (NDS) tested killed > 90% of B. burgdorferi cells. In contrast, normal mouse and rabbit sera killed < or = 22% of the Borrelia. Anti-B. burgdorferi antibodies could not be detected in any normal sera by indirect fluorescent antibody assay (IFA). Sera collected from deer 6 wk after exposure to B. burgdorferi by tick feeding exhibited IFA titers of 1:256, whereas sera from mice and rabbits similarly exposed had titers of > 1:1,024. Heat treatment (56 C, 30 min) of NDS reduced borreliacidal activity, with < 20% of the B. burgdorferi cells killed, suggesting complement-mediated killing. The chelators EGTA and EDTA were used to block the classical or both the classical and alternative complement pathways, respectively. Addition of 10 mM EGTA to NDS had a negligible effect on borreliacidal activity, with > 90% of the cells killed. Addition of 10 mM EDTA reduced the killing to approximately 30%, whereas the addition of Mg2+ (10 mM) restored borreliacidal activity to NDS. The addition of zymosan A, an activator of the alternative pathway, increased the survival of B. burgdorferi cells to approximately 80% in NDS. These data suggest that the alternative complement activation pathway plays a major role in the borreliacidal activity of NDS. Additionally, 10 mM EGTA had almost no effect on the killing activity of B. burgdorferi-exposed deer sera, suggesting that the classical pathway is not involved in Borrelia killing, even in sera from B. burgdorferi-exposed deer.

Antioxidant activities of estrogens against aqueous and lipophilic radicals; differences between phenol and catechol estrogens

Natural estrogens have much greater radical-scavenging antioxidant activity than has previously been demonstrated, with activities up to 2.5 times those of vitamin C and vitamin E. The biological significance of this finding remains to be elucidated. In this work the antioxidant activity of a range of estrogens (phenolic, catecholic and stilbene-derived) has been studied. The activity of these substances as hydrogen-donating scavengers of free radicals in an aqueous solution has been determined by monitoring their relative abilities to quench the chromogenic radical cation 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS*+). The results show that the order of reactivity in scavenging this radical in the aqueous phase is dependent on the precise estrogenic structure, with phenolic estrogens being more potent antioxidants than catecholestrogens or diethylstilbestrol. The ability of the same estrogens to scavenge lipid phase radicals has also been assessed, determined by the ex vivo enhancement of the resistance of low-density lipoprotein (LDL) to oxidation; the order of efficacy is different from that in the aqueous phase, with the phenolic estrogens estriol, estrone and 17beta-estradiol being less potent than 2-hydroxyestradiol, 4-hydroxyestradiol, or diethylstilbestrol. In this lipid-based system, phenolic estrogens were found to be unable to regenerate alpha-tocopherol from LDL subjected to oxidative stress, while at the same time 2- and 4-hydroxyestradiol significantly delayed alpha-tocopherol loss. These results indicate that the various estrogens are good scavengers of free radicals generated in both the aqueous and the lipophilic phases. The antioxidant activity of an estrogen depends not only on the hydrophilic or lipophilic nature of the scavenged radical, but also on the phenol and catechol structures of the estrogen compound.

Could antioxidants play a role in high rates of coronary heart disease in the Czech Republic?

OBJECTIVES

To compare plasma levels of antioxidant vitamins in the Czech population with those in a western European population, and to investigate whether plasma levels of antioxidant vitamins in Czech population are related to risk of MI.

DESIGN

The study has two parts: a cross-sectional survey and a population based case-control study.

SETTING

Adult population in two districts of the Czech Republic, and London based civil servants group as the comparison.

SUBJECTS

A random sample of men and women aged 25-64y resident in two districts were selected for the cross- sectional survey. Subjects in the age group 40-49 y were compared to a sample of British civil servants of the same age enrolled in the Whitehall II Study. Men in the Czech sample served as controls to 52 male cases of first non-fatal myocardial infarction (MI) which occurred in the same population. Plasma samples were obtained from venepuncture during an interview in hospital in the population sample and immediately after hospitalization in the MI cases.

MAIN OUTCOME MEASURES

Plasma levels of beta-carotene and alpha-tocopherol, and the event of MI. Identical protocol and one laboratory was used for all analyses.

RESULTS

The mean plasma levels of beta-carotene and alpha-tocopherol in healthy Czech men and women were substantially lower than in a subsample of British civil servants examined in the same laboratory. Smoking was strongly related to beta-carotene in both populations but differences between Czechs and Brits were present in both smokers and non-smokers. In the case-control study among Czech men, low levels of the vitamins were strongly related to an increases risk of MI. Age-adjusted odds ratios for concentrations below the median were 3.33 (95% confidence interval 1.43-8.33) for beta-carotene and 1.89 (0.94-3.45) for alpha-tocopherol; further adjustment for a range of variables reduced these estimates only slightly.

CONCLUSIONS

Plasma concentrations of antioxidants in the Czech population appeared to be very low, and men with low levels of these substances are at increased risk of MI. This indicates that sub-optimal intake of antioxidants or related dietary factors may have played a role in the high rates of coronary heart disease in this population.

Isolation of Cryptosporidium parvum and Cyclospora cayetanensis from vegetables collected in markets of an endemic region in Peru

Cryptosporidium parvum and Cyclospora cayetanensis are protozoan pathogens that cause prolonged diarrhea in both immunocompetent and immunocompromised hosts. Cryptosporidium parvum can be transmitted via the fecal-oral route, while the exact mechanisms of transmission of Cyclospora cayetanensis have not been fully determined. Humans appear to be the sole host for the latter and a distinct seasonality has been observed in endemic areas around the world. Samples of vegetables were collected at several small markets in a periurban slum in Peru during the seasons of high and low incidence. The vegetables were washed, the supernatants were collected and centrifuged, and the pellets were resuspended in a solution of 2.5% potassium dichromate. Pellets were examined using direct microscopic observation, acid-fast staining, and immunofluorescent assays for C. parvum and Cyclospora cayetanensis oocysts. Samples were collected during three time periods: the season of low incidence, the beginning of the season of high incidence, and end of the season of high incidence. Of the total vegetables examined, 14.5% contained C. parvum oocysts and 1.8% had Cyclospora oocysts. Thus, market vegetables may provide a route by which Cryptosporidium and Cyclospora can be transmitted. Our study also suggests that washing vegetables does not completely remove Cryptosporidium and Cyclospora oocysts.

Reference values for alpha-tocopherol and beta-carotene in the Whitehall II Study

Plasma alpha-tocopherol, beta-carotene, serum lipids and their derived ratios were determined in British Civil Servants (n = 7177) at the second medical examination of the Whitehall II Study, a longitudinal study of cardiovascular disease. For plasma alpha-tocopherol the non-parametric 95% reference interval (90% confidence limits) for the total population was: 11.1 (10.9-11.3)-51.5 (50.6-52.7) mumol/l. For plasma beta-carotene the non-parametric reference interval for the total population was: 0.05 (0.05-0.05)-2.14 (2.08-2.21) mumol/l. The latter interval was wider than those previously published with a higher mean (0.61 mumol/l) and median (0.75 mumol/l). Plasma beta-carotene concentrations were higher in women than men with age-adjusted means of 0.70 and 0.57 mumol/l respectively (p < 0.001). This may reflect differences in diet, lifestyle and metabolism between the sexes. The alpha-tocopherol/cholesterol ratio, as in other surveys, did not vary with age. Among men, current- and ex-smokers had a higher alpha-tocopherol/cholesterol ratio than never-smokers with age-adjusted means of 4.18, 4.19 mumol/mmol and 4.05 mumol/mmol respectively. This difference is as yet unexplained. Follow-up of these subjects will help to clarify the role of antioxidant nutrients as protective factors for cardiovascular disease and cancer.

Factors influencing the antioxidant activity determined by the ABTS.+ radical cation assay

This study introduces a simple direct antioxidant assay, based on the reduction of the ABTS.+ radical cation, and compares it with the myoglobin/ABTS.+ assay. The methods give closely similar results, establishing that the antioxidants studied to date in the latter assay act by scavenging the ABTS.+ radical cation and not by inhibiting its formation through reduction of ferryl myoglobin or reaction with H2O2.

Antioxidant activity of phytoestrogenic isoflavones

The aim of this work was to determine the antioxidant activities of a range of phytoestrogenic isoflavones. The antioxidant activity in the aqueous phase was determined by means of the ABTS.+ total antioxidant activity assay. The results show that the order of reactivity in scavenging the radical in the aqueous phase is genistein > daidzein = genistin approximately equal to biochanin A = daidzin > formononetin approximately equal to ononin, the latter displaying no antioxidant activity. The importance of the single 4'-hydroxyl group in the reactivity of the isoflavones, as scavengers of aqueous phase radicals, as well as the 5'7-dihydroxy structure is demonstrated. Examination of their abilities to enhance the resistance of low density lipoproteins to oxidation supports the observation that genistein is the most potent antioxidant among this family of compound studied, both in the aqueous and in the lipophilic phases.

Serum total antioxidant activity after myocardial infarction

Serum total antioxidant activity (TAA), albumin and uric acid were measured on admission, and for the next 2 days in 56 patients suffering myocardial infarction, 20 of whom received streptokinase. The 'antioxidant gap', the difference between the serum TAA and the sum of the serum albumin and uric acid activity, was calculated. No significant changes in serum total antioxidant activity were observed in either group of patients between admission, day 1 and day 2. However, a decline in the 'antioxidant gap' after myocardial infarction was associated with a significantly higher mortality.

Entomological correlates of Babesia microti prevalence in an area where Ixodes scapularis (Acari:Ixodidae) is endemic

Zoonotic prevalence of Babesia microti Franca piroplasms infecting white-footed mice, Peromyscus leucopus Rafinesque, was determined at 34 sites in Rhode Island where nymphal blacklegged tick, Ixodes scapularis Say, densities ranged from low to hyperabundant (1.7-525.3 nymphs per hour of flagging). Babesia was only detected at sites where tick abundance was moderate to high (> 20 nymphs per hour of flagging) and appeared to exhibit a clumped distribution. Where B. microti was detected, the mean number of nymphal ticks collected per hour of flagging was 229.2 compared with a mean of 40.1 at sites where Babesia was not detected. By combining the spatial occurrence of Babesia with a tick density database in a geographic information system, it may be possible to predict the pattern of zoonotic and human infection with B. microti.

The antioxidant properties of theaflavins and their gallate esters--radical scavengers or metal chelators?

The antioxidant properties of theaflavins and their gallate esters were studied by investigating their abilities to scavenge free radicals in the aqueous and lipophilic phases. The total relative antioxidant activities in the aqueous phase were assessed by measuring their direct ABTS.+ radical scavenging abilities, and by their efficacies in inhibiting the degradation of deoxyribose induced by iron. The propensities for enhancing the resistance of LDL to oxidation mediated by Cu2+ were also measured. The results show that the hierarchy of reactivity of these compounds as antioxidants is: theaflavin digallate > 3'-monogallate = 3-monogallate > theaflavin. Spectroscopic studies show that all the compounds chelate iron and copper; enhanced absorbance in the visible region is observed in the case of the iron-digallate complex, but not with copper.

Are whole extracts and purified glucosinolates from cruciferous vegetables antioxidants?

Fruits and vegetables contain several classes of compounds that can potentially contribute to antioxidant activity, including vitamins, simple and complex phenolics, sulphur-containing compounds and glucosinolates. The glucosinolates are found in high concentration in many cruciferous vegetables, and it is well established that their breakdown products induce endogenous antioxidant defences such as quinone reductase and glutathione S-transferase in cells and in vivo. Despite the anticarcinogenic effect of these compounds in animal models, the direct antioxidant properties of this class of compounds have not been systematically studied. We therefore examined the free radical-scavenging properties of representative extracts and of purified glucosinolates from cruciferous vegetables, by measuring their effect on ascorbate- or NADPH/iron-induced peroxidation of human liver microsomes, ascorbate/iron-induced peroxidation on phospholipid liposomes, iron chelation and hydroxyl radical scavenging using the deoxyribose assay, total antioxidant potential using ABTS (2,2'-azinobis(3-ethyl-benzothiazoline-6-sulphonate)) and the bleomycin assay. Most of the extracts from cruciferous vegetables exhibited some antioxidant properties, although extracts from cooked Brussels sprouts increased the rate of microsomal lipid peroxidation. The effects in these assays were dependent upon processing and species of crucifer, and the glucosinolate content appeared to play a minor role in these effects, since purified glucosinolates exhibited only weak antioxidant properties. The total antioxidant activities of extracts from cooked and autolysed Brussels sprouts were identical within experimental error. This is probably due to the content of phenolics which is unaltered by autolysis, despite the differences between these samples in other assays especially NADPH-iron-induced lipid peroxidation of human liver microsomes. The results demonstrate that glucosinolates are unlikely to account for the direct antioxidant effects of extracts from cruciferous vegetables.

Antioxidant activities of carotenes and xanthophylls

The purpose of this study was to assess the relative antioxidant activities of a range of carotenes and xanthophylls through the extent of their abilities to scavenge the ABTS(.+) radical cation. The results show that the relative abilities of the carotenoids to scavenge the ABTS(.+) radical cation are influenced by the presence of functional groups with increasing polarities, such as carbonyl and hydroxyl groups, in the terminal rings, as well as by the number of conjugated double bonds.

Lipids, lipoproteins, antioxidants and glomerular and tubular dysfunction in type 1 diabetes

We aimed to examine the relationship of serum lipids, lipoproteins, apolipoproteins and antioxidants with renal dysfunction as measured by urinary excretion of albumin and of retinol binding protein (RBP) in insulin-dependent diabetes mellitus (IDDM). We studied 121 patients with IDDM. Glomerular function was assessed as the urinary albumin/creatinine ratio (UA/UC), and tubular function as the urinary retinol-binding protein/creatinine ratio (UR/UC), both measured in three early morning spot urine samples. The mean (range) UA/UC was 1.95 mg/mmol (0.3-476.5) and UR/UC was 17.5 micrograms/mmol (1.0-1853.8). 17% of the patients had a UA/UC > 3 mg/mmol and 33% had a UR/UC > 20 micrograms/mmol. Significant positive correlations were observed between both UA/UC and UR/UC and the following: serum total cholesterol (P < 0.005); triglycerides (P < 0.001); apolipoproteins A-I (P < 0.05), A-II (P < 0.02) and B (P < 0.002); glycated haemoglobin (P < 0.002). No significant associations were found with serum vitamin E, beta-carotene or total antioxidant activity. In multiple regression, only UA/UC was independently associated with serum apo B and cholesterol concentrations. In conclusion, in IDDM glomerular dysfunction, as measured by UA/UC, is associated with elevated serum cholesterol, triglycerides, apo B, apo A-I and apo A-II, but not with HDL cholesterol or antioxidant status. Tubular dysfunction tends to occur with increasing albuminuria, but it is not independently associated with serum lipid, lipoprotein, apolipoprotein or antioxidant levels.

Structure-antioxidant activity relationships of flavonoids and phenolic acids

The recent explosion of interest in the bioactivity of the flavonoids of higher plants is due, at least in part, to the potential health benefits of these polyphenolic components of major dietary constituents. This review article discusses the biological properties of the flavonoids and focuses on the relationship between their antioxidant activity, as hydrogen donating free radical scavengers, and their chemical structures. This culminates in a proposed hierarchy of antioxidant activity in the aqueous phase. The cumulative findings concerning structure-antioxidant activity relationships in the lipophilic phase derive from studies on fatty acids, liposomes, and low-density lipoproteins; the factors underlying the influence of the different classes of polyphenols in enhancing their resistance to oxidation are discussed and support the contention that the partition coefficients of the flavonoids as well as their rates of reaction with the relevant radicals define the antioxidant activities in the lipophilic phase.

Exploring factors of perceived social performance, health and personal control among retired seniors and seniors owning home-based businesses in non-metropolitan counties

Persons (n = 77) over age fifty-five and living within nine non-metropolitan counties participated in this study to determine if the factors of social performance, health, and personal control were perceived differently by those operating a home-based business than those individuals fully retired from any employment. No significant differences were found between the groups in terms of health or desire for self-control, though the home-based business owners were found to desire more social contact than non home-based business owners. In addition, those home-based business owners who desired high degrees of self-control, found operation of a business from the home to be highly satisfactory.

Levels of antioxidant nutrients in plasma and low density lipoproteins: a human volunteer supplementation study

A human supplementation study was undertaken in order to investigate the correlation between the intake of individual daily dosages of vitamin E (300 mg), vitamin C (250 mg), or beta-carotene (15 mg) of eight week duration and their uptake in vivo in plasma and LDL. The effects of a combined supplement of vitamin E, vitamin C and beta-carotene (Redoxon protector-75 mg, 150 mg, 15 mg respectively) were also investigated. The results show that on supplementation with the individual antioxidants the increases in plasma alpha-tocopherol:cholesterol levels lie in the 1.5-2 fold range and the beta-carotene:cholesterol ratios give a mean 3.5 fold enhancement. The combined supplement containing the same level of beta-carotene as the single dosage achieved comparative levels of uptake in plasma. The level of plasma vitamin C appears to be maximal at about 100 microM regardless of the pre-supplementation level.

Polyphenolic flavanols as scavengers of aqueous phase radicals and as chain-breaking antioxidants

The purpose of this investigation was to establish the relative antioxidant activities in vitro of the flavanolic polyphenols, the catechins, and catechin-gallate esters. The relative antioxidant potentials were measured against radicals generated in the aqueous phase and against propagating lipid peroxyl radicals. The results show that in the aqueous phase their order of effectiveness as radical scavengers is epicatechin gallate (ECG) > epigallocatechin gallate (EGCG) > epigallocatechin (EGC) > gallic acid (GA) > epicatechin congruent to catechin; against propagating lipid peroxyl radical species, epicatechin and catechin are as effective as ECG and EGCG, the least efficacious being EGC and GA. This is consistent with their relative abilities to protect against consumption of LDL alpha-tocopherol. The results are discussed in the context of the most relevant antioxidant constituents of green tea extracts.

Total antioxidant activity of low density lipoproteins and the relationship with alpha-tocopherol status

A rapid method is described for measuring the antioxidant activity of low density lipoproteins. Studies were undertaken on individuals attending a hyperlipidaemia clinic, an unsupplemented group and a group after supplementation with 300 mg dl-alpha-tocopherol acetate for nine weeks. The results show a positive correlation between the antioxidant activity and alpha-tocopherol content of LDL in the supplemented group.

The relative antioxidant activities of plant-derived polyphenolic flavonoids

The relative antioxidant activities, against radicals generated in the aqueous phase, of a range of plant-derived polyphenolic flavonoids, constituents of fruit, vegetables, tea and wine, have been assessed. The results show that compounds such as quercetin and cyanidin, with 3',4' dihydroxy substituents in the B ring and conjugation between the A and B rings, have antioxidant potentials four times that of Trolox, the vitamin E analogue. Removing the ortho-dihydroxy substitution, as in kaempferol, or the potential for electron delocalisation by reducing the 2,3 double bond in the C ring, as in catechin and epicatechin, decreases the antioxidant activity by more than 50%, but these structures are still more effective than alpha-tocopherol or ascorbate. The relative significance of the positions and extents of hydroxylation of the A and B rings to the total antioxidant activity of these plant polyphenolics is demonstrated.

Antioxidant activity of saliva and periodontal disease

The antioxidant activity of saliva has been investigated in 28 apparently healthy individuals and seven dental patients with periodontal disease. The results show that the major aqueous antioxidant component of whole saliva is uric acid, with lesser contributions from ascorbic acid and albumin. All are present at lower concentrations than those found in the plasma water. The total antioxidant activity (TAA) of saliva correlates (r2 = 0.972) with the concentration of uric acid, which contributes more than 70% of the TAA. Stimulation of salivary flow is associated with increased production of antioxidants. The antioxidant potential of saliva does not appear to be compromised in patients with periodontal disease but this may relate to the antioxidant flow from the gingival crevicular fluid.

Bilirubin and ascorbate antioxidant activity in neonatal plasma

Extremely low birth weight premature infants have been known for many years to have limited antioxidant protective capacity, especially with reference to those antioxidant components which do not cross the placenta until the third trimester of gestation. In this study the total antioxidant activity and the concentrations of individual antioxidants in plasma from premature neonates (27 +/- 2 weeks gestation) compared to term babies (38-41 weeks gestation) have been examined. The results show elevated levels of ascorbate at birth in the plasma of premature neonates compared with those of term babies, but the total plasma antioxidant status of the premature babies is significantly lower than that of term babies. At 5 days post-partum the ascorbate levels are within the normal adult range and plasma bilirubin levels are considerably enhanced in both groups, while the total plasma antioxidant status of the premature neonates has increased. Analysis of the relationship between the total plasma antioxidant activity and the bilirubin concentration show a direct, highly significant correlation for the term group, r2 = 0.774, consistent with significance of bilirubin as a plasma antioxidant.

A novel method for measuring antioxidant capacity and its application to monitoring the antioxidant status in premature neonates

1. A new method has been developed for measuring the total antioxidant capacity of body fluids and drug solutions, based on the absorbance of the ABTS.+ radical cation. 2. An automated method for use on a centrifugal analyser, as well as a manual method, is described. 3. The procedure has been applied to physiological antioxidant compounds and radical-scavenging drugs, and an antioxidant ranking was established based on their reactivity relative to a 1.0 mmol/l Trolox standard. 4. The Trolox equivalent antioxidant capacity of plasma from an adult reference population has been measured, and the method optimized and validated. 5. The method has been applied to investigate the total plasma antioxidant capacity of neonates and how this may be compromised in prematurity.

Consideration on some hormone binding proteins patterns during pregnancy

Serum concentrations of sex hormone binding globulin, transcortin, thyroxine binding globulin, transthyretin together with retinol binding protein, ceruloplasmin, transferrin and albumin were measured sequentially in pregnant women in order to derive more definite suppositions relating to the prime function of hormone binding proteins. Thus, the fact that except for transthyretin all other specific hormone binding proteins exhibited appreciable but significantly variable increases would suggest: a) the apparent existence of more complex mechanisms regulating protein metabolism during pregnancy than hitherto postulated (i.e. the general notion of an integrated estrogen influence); b) a major and distinctive role for each of the hormone binding proteins is plausible since alterations in hormonal requirements by the fetus as pregnancy progresses can not be provided by the almost constant transplacental transfer rate of the "free" hormone moiety.

Hearing in the elderly: the Framingham cohort, 1983-1985. Part I. Basic audiometric test results

Many studies have documented the decline in auditory function with age. We broaden that data base in this the first of a series of reports emanating from the auditory testing of the Framingham cohort during biennial exam 18. The results of the auditory questionnaire, hearing sensitivity, acoustic compliance measures, and word recognition tests obtained from 1662 men and women in their 60th through 90th decades are presented. Pure-tone thresholds increased with age but the rate of change with age did not differ by gender even though men had poorer threshold sensitivity. Maximum word recognition ability declined with age more rapidly in men than in women and was poorer in men than in women at all ages. Acoustic compliance and middle ear pressure did not vary with gender or age. Acoustic reflex thresholds to a contralateral stimulus at 1 kHz increased slightly with age, more in women than in men; ipsilateral acoustic reflex thresholds did not vary with age or gender. Hearing aids were being used in only 10% of subjects likely to benefit from amplification.