Nuclear magnetic resonance imaging of experimentally induced liver disease

Experimental animal models of hepatitis, fatty liver, and hepatic iron overload were evaluated using a 3.5-kGauss nuclear magnetic resonance (NMR) imaging system. Increases in image intensity measurements and in T2 relaxation times equalled the sensitivity of histologic findings for the detection of early stages of hepatitis. A significant shift in T1 relaxation times characterized the early stages of hepatic necrosis. Liver triglyceride content correlated significantly with increases in NMR intensity measurements (p less than 0.01); however, changes in liver water content had a much greater influence on intensity, T1, and T2. Thus, it may be possible to distinguish hepatitis from benign fatty liver. Liver iron content correlated with decreases in NMR intensity measurements (p less than 0.001), and iron levels as low as 1.2 mg/g were detected. NMR may more specifically identify hepatocellular iron overload than do other techniques that do not distinguish hepatocellular from reticuloendothelial iron.

Prader-Willi Syndrome after age 15 years

Twenty-four patients, all of them over 15 years, with the Prader-Willi syndrome are described. Obesity, often extreme, associated with an insatiable appetite, was their principal handicap and this was made worse by educational subnormality and hypogonadism. Three of the them developed diabetes. Each attended a special school or an adult training centre. Although most of them were of short stature and had scoliosis, 2 were tall but they even more severely mentally retarded than is usually the case. Nine other patients died aged between 3 and 23 years. The most common cause of death was cor pulmonale.

Marine reserves: fish life history and ecological traits matter

Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.

Relevance of serum bile acid profile in the diagnosis of intrahepatic cholestasis of pregnancy in an high incidence area: Portugal

OBJECTIVE(S)

The present work was conducted to clarify the relevance of usual liver function tests, and define the most predictive serum bile acid profile for diagnosis of intrahepatic cholestasis of pregnancy (ICP).

STUDY DESIGN

This study comprised 20 healthy nonpregnant women and 77 pregnant women in the last trimester of pregnancy, from which 38 were normal pregnancies, and 39 suffered from ICP. Liver function tests were evaluated by routine laboratory techniques, conjugated bile acids were analysed by high-performance liquid chromatography, and unconjugated forms were measured by an enzymatic-fluorimetric assay.

RESULTS

During the third trimester in normal pregnancy, increased concentration of conjugated species affected all primary bile acids, although only significantly for glycocholic acid. Moreover, deoxycholic acid proportion decreased when compared with healthy nonpregnant women. Important ICP-induced changes in serum profiles of amidated bile acids were observed, involving both a marked increase in cholic acid concentration and a shift towards a higher proportion of taurine-conjugated species. Among routine liver tests, alanine aminotransferase and conjugated bilirubin were the most common indicators of ICP.

CONCLUSION(S)

In the early diagnosis and follow-up of ICP, the most predictive and accurate markers (efficiency 100%) were: (i) TBA concentration in serum >11.0 micromol(-1): (ii) cholic/chenodeoxycholic acid ratio >1.5 and cholic acid percentage >42%: (iii) glycine/taurine bile acid ratio <1.0 or glycocholic acid concentration >2.0 micromol(-1). Accurate diagnosis based on sensitive biochemical markers followed by appropriate treatment may improve both pregnancy outcome and newborn prognosis.

Noninvasive quantitation of liver iron in dogs with hemochromatosis using dual-energy CT scanning

The concentration of iron deposited in the livers of two dogs with experimentally induced iron overload was determined by use of dual energy computerized tomographic (CT) scanning. A phantom was constructed, containing known amounts of iron-dextran solutions. CT scans of the phantoms, at 80 and 120 kVp, corrected for the response of water, showed a linear relationship between known iron concentrations and difference in CT number at the two scanning energies, with a change of 24 H units per 1000 mg% iron. Using the graph of this linear relationship, the amount of iron in dog liver was predicted, compared with the amount of iron measured from biopsy specimens, and analyzed by neutron activation analysis. A close correlation existed between predicted liver iron and measured iron concentration (r = 0.99). Dual-energy CT scanning appears to provide an accurate, noninvasive method of quantitating liver iron.

Parental self-efficacy and morbidity in pediatric asthma

This study investigated the relationship between parental self-efficacy and asthma-related morbidity. Participants included 139 parents of children (ages 5-8) who were diagnosed with asthma and were primarily from lower-income and minority backgrounds. Parents completed a 22-item measure of self-efficacy; factor analysis was conducted on this measure, yielding two factors: learned helplessness and self-efficacy. Correlational analyses indicated that higher scores on the learned helplessness factor were significantly related to increased asthma-related morbidity for the majority of morbidity variables. The self-efficacy factor was significantly related to days of school missed. Regression analyses conducted with the factor scores and the morbidity variables provide further support that the learned helplessness factor accounts for a significant amount of the variance in asthma morbidity for many of the variables studied, while the self-efficacy factor was related to only a few. Although improving health outcomes of children with asthma is a multifaceted process, the results of this study suggest that targeting parental self-efficacy, particularly with parents who are experiencing high levels of perceived learned helplessness, may be a helpful component of an intervention program with this population.

Sediment and water nutrients and microalgae in a coastal shallow lagoon, Ria Formosa (Portugal): implications for the Water Framework Directive

Coastal shallow lagoons are considered to be highly important systems, which have specific biogeochemical cycles and characteristics. The assessment of sediment-water interfaces is essential to understand nutrient dynamics and to evaluate the vulnerability to eutrophication, especially in regions of restricted water exchange (RRE), such as the Ria Formosa, which have natural conditions for the accumulation of nutrients. Water samples were collected during the years of 2006 and 2007-08 for nutrients, chlorophyll a and dissolved oxygen. Sediment samples were also collected for pore water nutrients and microphytobenthic chlorophyll a. Measurements of temperature, salinity and photosynthetic active radiation were also taken. The lagoon salinity is affected by occasional strong rainfall events. From comparison with previous work, a decrease in the nitrogen concentration in the water column can be observed, which may indicate an improvement of the water quality. Pore water nutrient concentrations were significantly larger than in the water column. Sediment-water exchanges are considered to be the most important processes in nutrient dynamics of the lagoon. Benthic microalgal biomass was also large compared with that of the phytoplankton. It represents about 99% of the total microalgal chlorophyll biomass of the system. The lagoon also contains (discontinuous) meadows of intertidal seagrass, but we did not study these. Due to the importance of sediments, the standard monitoring plans required by the Water Framework Directive may fail to track changes in the nutrient conditions and the microalgal responses to them.

Hepatic cirrhosis: magnetic resonance imaging

The effect of periportal collagen deposition on magnetic resonance images and T1 and T2 relaxation times was studied in the rat. Hepatic cirrhosis was induced in 29 rats by chronic intraperitoneal thioacetamide injections. Another 14 rats in which liver abnormalities did not develop were used as controls. The rats were imaged using a small-bore resistive magnet. Histologic correlations and hydroxyproline measurements were performed to document the changes in periportal collagen deposition. The T1 and T2 relaxation times, determined both in vivo and in vitro with spectroscopy, were compared between the normal group and the group with moderate to severe histologic evidence of cirrhosis. The deposition of two to four times the normal amount of collagen in the liver did not affect the T1 or T2 relaxation time. Relatively pure periportal collagen fibrosis does not appear to affect the magnetic resonance image or T1 or T2 relaxation times of the rat liver.

Effect of bilirubin on erythrocyte shape and haemolysis, under hypotonic, aggregating or non-aggregating conditions, and correlation with cell age

The effect of unconjugated bilirubin on the morphology and haemolysis of human erythrocytes was accomplished under distinct incubation conditions: (i) hypotonic medium, with bilirubin concentrations ranging from 1 x 10(-9) to 1 x 10(-4) mol l-1; (ii) isotonic medium, with 171 mumol l-1 bilirubin, in the absence of albumin (aggregating conditions), using non-separated and age-fractionated erythrocytes; (iii) isotonic medium, with 171 mumol l-1 bilirubin, in the presence of a surplus of human serum albumin (non-aggregating conditions), and using sulfisoxazole as a bilirubin displacer (bilirubin/albumin and sulfisoxazole/ albumin molar ratios of 0.5 and 4.0, respectively). Our data showed that low concentrations of bilirubin (1 x 10(-7) to 1 x 10(-5) mol l-1) protect against hypotonic haemolysis and induce crenation, while higher bilirubin concentrations induce haemolysis and lead to membrane disruption. When aggregating conditions were used, these phenomena were reproduced, the younger cells being significantly more susceptible to crenation while the older erythrocytes showed increased susceptibility to haemolysis. In non-aggregating conditions, haemolysis was virtually absent, though crenation was evident. Based on the above observations we conclude that the first step of erythrocyte bilirubin toxicity is crenation due to an expansion of the outer membrane leaflet by bilirubin mono-anion location. This effect is more evident in younger cells and explains the protection against the hypotonic haemolysis. Insertion of bilirubin deeper into the bilayer, facilitated by higher concentrations (> or = 1 x 10(-4) mol l-1) and cell age, produces an unstable situation, where bilirubin acid aggregation is apparently the main cause for haemolysis and cell destruction.

Experimental pulmonary emboli detected using magnetic resonance

Experimental pulmonary emboli that were labelled with non-magnetic barium threads and produced using aminocaproic acid were introduced into the internal jugular veins of five dogs. Transverse axial magnetic resonance (MR) images (0.35 T, 15 MHz) and CT scans (2.0 or 4.8 seconds, G.E. 9800 or 8800 scanner) were obtained from the lung apex to base in each animal. The MR images were gated to the cardiac cycle, and spin echo techniques were used (TR = gated to the cardiac cycle; TE = 28 and 56 msec). Nineteen sites of embolism were determined from the CT scans. Two observers, who had no knowledge of the number or position of the emboli, individually assessed the MR images and marked the sites of emboli on clear acetate overlays. Each observer detected 12 of 19 emboli (63%) and each had one false positive result. Of the 19 emboli, six were central or parahilar and 13 were in the outer two thirds of the lungs. Three (first observer) or four (second observer) of the seven false negative results were central. In retrospect, two central emboli were mistaken for hilar fat. One peripheral embolus was not visible, even in retrospect. The potential for MR to demonstrate relatively small pulmonary emboli has been shown. Clinical trials in patients seem warranted.

MR relaxometry imaging. Work in progress

Acquisition of relaxation rate dispersion curves from magnetic resonance images was demonstrated on a clinical, whole-body imaging system. Study of the behavior of relaxation rates over a range of field strengths probes the structural environment of imaged hydrogen protons and reveals information about the composition of tissue. The authors determined relaxation rates in extremities and heads of healthy volunteers. The sensitivity of the measurement is sufficient to obtain a distinctive relaxation rate dispersion behavior for different tissues.

Older adults benefit from more widespread brain network integration during working memory

Neuroimaging evidence suggests that the aging brain relies on a more distributed set of cortical regions than younger adults in order to maintain successful levels of performance during demanding cognitive tasks. However, it remains unclear how task demands give rise to this age-related expansion in cortical networks. To investigate this issue, functional magnetic resonance imaging was used to measure univariate activity, network connectivity, and cognitive performance in younger and older adults during a working memory (WM) task. Here, individuals performed a WM task in which they held letters online while reordering them alphabetically. WM load was titrated to obtain four individualized difficulty levels with different set sizes. Network integration-defined as the ratio of within-versus between-network connectivity-was linked to individual differences in WM capacity. The study yielded three main findings. First, as task difficulty increased, network integration decreased in younger adults, whereas it increased in older adults. Second, age-related increases in network integration were driven by increases in right hemisphere connectivity to both left and right cortical regions, a finding that helps to reconcile existing theories of compensatory recruitment in aging. Lastly, older adults with higher WM capacity demonstrated higher levels of network integration in the most difficult task condition. These results shed light on the mechanisms of age-related network reorganization by demonstrating that changes in network connectivity may act as an adaptive form of compensation, with older adults recruiting a more distributed cortical network as task demands increase.

School-based identification of asthma in a low-income population

The increase in the prevalence, morbidity, and mortality of asthma among children over the last decade has been well documented, especially among low-income minority children. Hypotheses for the increases in morbidity and mortality include limited access to primary care services and the failure to recognize the presence and severity of asthma. The University of Miami Pediatric Mobile Clinic (Mobile Clinic) Asthma Intervention Program is designed to identify underserved asthmatic children at school and offer them culturally sensitive care. Nine elementary schools with low income, predominantly Hispanic and African-American populations regularly served by the Mobile Clinic, were chosen for study participation. All 5,800 students who were enrolled in kindergarten through third grade were given letters at the time of registration by their homeroom teachers about the asthma program. Caretakers who returned the questionnaire and reported that the student had asthma symptoms were invited to have the student undergo a medical evaluation in the Mobile Clinic. Over a 2-year period, caretakers of 423 students (7.3% of all students) expressed an interest in further evaluating their child's respiratory health. Of these, we enrolled and evaluated 154 in the Mobile Clinic's Asthma Intervention Program. The Mobile Clinic physicians identified 145 of the enrollees as having asthma. These results indicate that in elementary schools serving predominantly low-income minority populations, a large fraction of the asthmatic population (estimated prevalence, 6-10%) can be identified by a school-based letter. Further, in a subset of asthmatic students (children of interested caretakers), there is good agreement between caretaker responses and physician diagnosis of asthma. Since school attendance is mandatory, school-based methods may be an effective method for identifying low-income children with asthma.

A preliminary study of MRI quantification of simulated calcified pulmonary nodules

The potential of magnetic resonance imaging (MRI) quantification of calcium for the evaluation of pulmonary nodules was investigated in simulated nodules. Calcium salts do not contain mobile protons and thus have no signal on MR proton images. To determine whether the absence of signal from partially calcified nodules could be quantified, we studied simulated nodules containing known quantities of calcium salts. The soft tissue equivalent material was an agar-gelatin mixture (T1:1100-1500 msec; T2: 59-62 msec). In the first experiments, glass tubes were filled with the mixture, which contained suspensions of calcium carbonate (CaCO3) or silica dioxide (Si02), and were subjected to computed tomography (CT) scanning and MR imaging. In a second series of studies CaCO3 particles of various sizes (and therefore different surface-to-volume ratios) were similarly suspended and subjected to CT scanning and MR imaging. In a third series hydroxyapatite (HA) suspensions of different sizes were similarly studied. CaCO3 produced a significant reduction in MR hydrogen density and signal intensity of the agar-gelatin mixture. Reduction in T1 and T2 relaxation times was inconsistent and not related to particle size. CaCO3 produced its effect by soft-tissue displacement. HA (and Si02) caused a more marked fall in MR hydrogen density, signal intensity, and T1 and T2 relaxation times. The degree of the T1 and T2 effects was related to particle size, indicating a hydrophilic surface effect. The authors conclude that MRI quantification of calcium within pulmonary nodules (or other tissues) will be complex and will relate to the precise composition of the calcium salt and to the particle size of the aggregates.

Establishment of a coastal fish in the Azores: recent colonisation or sudden expansion of an ancient relict population?

The processes and timescales associated with ocean-wide changes in the distribution of marine species have intrigued biologists since Darwin's earliest insights into biogeography. The Azores, a mid-Atlantic volcanic archipelago located >1000 km off the European continental shelf, offers ideal opportunities to investigate phylogeographic colonisation scenarios. The benthopelagic sparid fish known as the common two-banded seabream (Diplodus vulgaris) is now relatively common along the coastline of the Azores archipelago, but was virtually absent before the 1990 s. We employed a multiple genetic marker approach to test whether the successful establishment of the Azorean population derives from a recent colonisation from western continental/island populations or from the demographic explosion of an ancient relict population. Results from nuclear and mtDNA sequences show that all Atlantic and Mediterranean populations belong to the same phylogroup, though microsatellite data indicate significant genetic divergence between the Azorean sample and all other locations, as well as among Macaronesian, western Iberian and Mediterranean regions. The results from Approximate Bayesian Computation indicate that D. vulgaris has likely inhabited the Azores for ∼ 40 (95% confidence interval (CI): 5.5-83.6) to 52 (95% CI: 6.32-89.0) generations, corresponding to roughly 80-150 years, suggesting near-contemporary colonisation, followed by a more recent demographic expansion that could have been facilitated by changing climate conditions. Moreover, the lack of previous records of this species over the past century, together with the absence of lineage separation and the presence of relatively few private alleles, do not exclude the possibility of an even more recent colonisation event.

Avaliação da radioiodoterapia com doses fixas de 10 e 15 mCi em pacientes com doença de graves

As opções terapêuticas para a hipertireoidismo da doença de Graves são as drogas antitireoidianas, a cirurgia e o radioiodo, porém nenhuma delas é considerada ideal pois não atuam diretamente na etiopatogênese da doença. O radioiodo vem sendo cada vez mais utilizado como primeira escolha, sendo um tratamento definitivo, seguro e de fácil administração. Há autores que preferem doses mais altas para induzir deliberadamente o hipotireoidismo, enquanto outros recomendam doses mais baixas que, a curto prazo, implicam menor incidência de hipotireoidismo e maior de eutireoidismo. Não há consenso sobre o melhor esquema de doses fixas a ser utilizado, sendo esse o principal enfoque deste estudo, no qual comparamos doses de 10 e 15 mCi. Dos 164 pacientes analisados, 61 (37,2%) foram submetidos a 10 mCi e 103 (62,8%), a 15 mCi de 131I. Na análise longitudinal, observou-se que a remissão do hipertireoidismo foi estatisticamente diferente no sexto mês (p < 0,001), sendo maior no grupo em que foi empregada a dose de 15 mCi. Contudo, foi semelhante nos dois grupos após 12 e 24 meses. É possível concluir que doses fixas de 10 e 15 mCi promovem semelhante remissão do hipertireoidismo após 12 meses de tratamento. A remissão do hipertireoidismo não teve associação com idade, sexo ou uso prévio de drogas antitireoidianas.

Effects of Fish Oil Supplementation on Oxidative Stress Biomarkers and Liver Damage in Hypercholesterolemic Rats

Metabolic syndrome, especially its component related to dyslipidemia, is related to the development of nonalcoholic fatty liver disease (NAFLD), which is a disease with a significant global prevalence. Supplementation with omega-3 polyunsaturated fatty acids emerged as a complementary therapeutic possibility for dyslipidemia, but its benefits are questioned. This paper aims at evaluating the effects of fish oil supplementation in rats with hypercholesterolemia induced by hypercholesterolemic diet (HD). The study design is based on an experimental model in which the animals were randomly divided into 3 groups: G1 (standard commercial feed + saline solution); G2 (hypercholesterolemic diet + saline solution) and G3 (hypercholesterolemic diet + fish oil) over a period of 16 weeks. Metabolic control parameters and oxidative stress biomarkers were evaluated according to standardized methodologies. The G3 group showed significantly lower values of plasma concentrations of TG, and hepatic myeloperoxidase as well as higher erythrocyte superoxide dismutase activity (p < 0.05). Regarding histopathological analysis, there was lipid accumulation in the liver of animals from group G2; meanwhile, hepatocytes reorganization and expressive reduction of lipid vacuoles and hepatic TG content was observed in group G3. This study demonstrated how fish oil supplementation reduced the plasma concentration and hepatic content of triglycerides, as well as liver tissue damage in histopathological analysis.

Recirculation of iopanoic acid after conjugation in the liver

The purpose of the investigation was to determine if an enterohepatic recirculation occurred for the metabolite of iopanoic acid. The major metabolite of iopanoic acid (Telepaque) in dog bile is the glucuronide conjugate. The identification and quantitation of glucuronide conjugate was accomplished by elemental analysis, paper chromatography, thin layer chromatography, fluorescent excitation analysis, and high pressure liquid chromatography. The stability of iopanoic acid glucuronide in refrigerated dog bile was confirmed. Known amounts of the glucuronide conjugate were instilled into the duodenum of 8 awake adult dogs, and bile collected for 8 hours. Between 19% and 53% (average 31%) of the administered dose was recovered in bile, thereby documenting the presence of an enterohepatic recirculation of conjugated iopanoic acid. The slow rise and plateau of the excretion curve suggests that either the compound is absorbed slowly, or that absorption depends upon deconjugation in the gut. The implications are discussed.

Regulation of the expression of interleukin-8 induced by 25-hydroxycholesterol in retinal pigment epithelium cells

PURPOSE

This study aimed at elucidating the molecular mechanisms involved in the regulation of IL-8 production by several oxysterols in retinal pigment epithelium (RPE) cells.

METHODS

A human cell line from RPE (ARPE-19) was used to test the role of cholesterol and several oxysterols (25-OH, 7-KC and 7β-OH) in the expression and secretion of IL-8. Expression of IL-8 was assessed by real-time PCR, while IL-8 secretion was evaluated by ELISA. PI3K-, MEK1/2-, ERK1/2- and NF-κB-specific inhibitors were used to assess the specific role of the several players on the regulation of IL-8 production by oxysterols. A gene-reporter assay for AP-1 activity was also conducted to evaluate the putative role of this transcription factor on IL-8 expression induced by oxysterols.

RESULTS

Here, we demonstrate that 25-OH specifically increases transcription and secretion of the cytokine IL-8 in ARPE-19 cells. Indeed, treatment of ARPE-19 with 25-OH, but not with 7-KC, 7β-OH or cholesterol, induced the secretion of IL-8 from cells. 25-OH also induced the activation/phosphorylation of ERK1/2 through a mechanism dependent on MEK, ERK1/2 and PI3K kinase activity. Real-time PCR and ELISA experiments demonstrated that 25-OH increased transcription and secretion of IL-8 through a mechanism that is dependent on ERK1/2 and PI3K activity. Furthermore, 25-OH triggered the activation/phosphorylation of the AP-1 component c-Jun and, consistently, increased the transcriptional activity of AP-1. Additionally, we also found that 25-OH decreases the levels of IκB and increases the nuclear levels of NF-κB p65 subunit and that inhibition of NF-κB activity partially prevents the increased secretion of IL-8 induced by 25-OH.

CONCLUSIONS

The results presented in this study suggest a role for 25-OH in inducing IL-8 production through pathways that are likely to involve AP-1 and NF-κB in ARPE-19 cells. Our data may also provide new molecular targets for the treatment of AMD.

Lycopene-Rich Extract from Red Guava (Psidium guajava L.) Decreases Plasma Triglycerides and Improves Oxidative Stress Biomarkers on Experimentally-Induced Dyslipidemia in Hamsters

This work assessed the effects of a 28-day treatment with lycopene-rich extract (LRE) from red guava fruit (Psidium guajava L.) on the lipid profile and oxidative stress in an experimental model of dyslipidemia. Male hamsters (116.5 ± 2.16 g) were fed with the AIN 93G diet containing casein (20%), coconut fat (13.5%) and cholesterol (0.1%). The animals were divided into four groups: normolipidemic control (standard feed; NC, n = 7); hypercholesterolemic control (HC, n = 7); LRE 25 mg/kg/day (LRE-25, n = 7) and LRE 50 mg/kg/day (LRE-50, n = 9). After treatment, plasma concentrations of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol (LDL-c), high-density lipoprotein (HDL) cholesterol (HDL-c), malondialdehyde (MDA-p) and myeloperoxidase (MPO), as well as erythrocytic superoxide dismutase (SOD-e) and the atherogenic index, were determined. Malondialdehyde (MDA-h), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD-h) levels were assessed. Feed intake (FI) and weight gain (WG) were also determined. The LRE-25 group presented significantly lower TG levels and atherogenic index than did the HC group (p < 0.05). Both LRE-25 and LRE-50 groups presented lower levels of MDA-p and MPO than did the HC group (p < 0.05). LRE demonstrated a promising effect against dyslipidemia and oxidative stress.

In vivo measurement of hepatic iodine concentration using fluorescent excitation analysis

Hepatic iodine concentration was measured in the live dog by external use of fluorescent excitation analysis. The number of characteristic photons produced by interaction of exciting radiation from an americium-241 source with iodine within the tissue is proportional to the tissue iodine concentrations. A correction is made for absorption of radiation by the abdominal wall and other tissues lying between the volume of liver being assayed and the detector collimator. The technique is applicable to the in vivo measurement of iodine concentrations from 0.5 to 40 mg/g. Accuracy of the technique is approximately +/- 10%, which is within the range of variation in iodine concentration at various sites within the liver. Radiation dose is low, and radiolabeled tracer compounds need not be used.

Syzygium cumini Nectar Supplementation Reduced Biomarkers of Oxidative Stress, Muscle Damage, and Improved Psychological Response in Highly Trained Young Handball Players

The purpose of this study was to investigate the effects of Syzygium cumini (SC) nectar supplementation on performance, markers of oxidative stress, muscle damage, and psychological response in Handball players. Twenty-five young athletes (age = 18.6 ± 2.4 years) from an elite high school national level Brazilian Handball team were randomized into two study groups: SC/Jamelon nectar (SC, n = 12) and placebo (n = 13). The subjects ingested 10 mL/kg/day of Jamelon nectar or placebo 30 min before the training sessions and immediately after training cessation, for 28 days. Body mass index (BMI) and percentage of fat mass were assessed using bioelectrical impedance analysis. Biomarkers of oxidative stress were measured by lipid peroxidation, which was quantified by malondialdehyde (MDA). Total antioxidant capacity (TAC), creatine kinase (CK) activity, and lactate dehydrogenase (LDH) were determined. The 20 m shuttle run test, vertical jump, and running anaerobic sprint test were assessed to verify performance and the fatigue index was calculated. The Profile of Mood States (POMS) questionnaire was used for psychological evaluation. Both groups demonstrated improved vertical jump performance and a decreased fatigue index over time but without significant differences between them regarding performance. There was statistically significance only for SC in CK, LDH, and MDA, and TAC was greater in the SC compared to placebo. Furthermore, only the SC group demonstrated improved mood disturbance and confusion after the intervention. In conclusion, the present study suggests that SC nectar supplementation reduced biomarkers of oxidative stress and muscle damage, and improved psychological response in young handball players.

Successful HAART is associated with high B-chemokine levels in chronic HIV type 1-infected patients

Chemokine receptors are used by HIV-1 for entry into CD4+ T cells. The beta-chemokines are capable of inhibiting HIV replication. This study measured beta-chemokine macrophage inflammatory protein (MIP)-1alpha and MIP-1beta levels and determined the CCR5 and CXCR4 expression on T cells in HIV-1-infected patients treated with HAART. The time of known HIV infection and time of HAART use were similar between failure and successful groups. The CD4+ T cell nadir was 163 vs. 251 cells/mm3, p = 0.07, for failure and successful groups, respectively. The successfully treated group, when compared with the failure group, had a higher median CD4+ T cells count (667 vs. 257 cells/mm3; p = 0.003) as well as higher spontaneous MIP-1alpha (median of 4390 vs. 802 pg/ml, p = 0.03) and MIP-1beta (median of 2416 vs. 1117 pg/ml, p = 0.001) levels. The untreated patients had a higher number and intensity of CCR5- and CXCR4-expressing T cells. Higher levels of chemokines were not related to nadir CD4+ T and current CD8+ T cell counts. Successfully treated patients were able to produce higher amounts of beta-chemokines and normalize the coreceptor overexpression on T cells. These findings may have clinical implications, such as a new strategy of using chemokines as adjuvants in anti-HIV therapy.