Restored antioxidant capacity parallels the immunologic and virologic improvement in children with perinatal human immunodeficiency virus infection receiving highly active antiretroviral therapy

Reversing bladder outlet obstruction attenuates systemic and tissue oxidative stress

What's known on the subject? and What does the study add? Oxidative damage in bladder tissue and systemic oxidative biomarkers were both found to be increased in rabbits with partial bladder outlet obstruction. It is shown that the reversal of partial bladder outlet obstruction will attenuate the systemic oxidative stress.

OBJECTIVE

To investigate whether partial bladder outlet obstruction (PBOO) increases systemic oxidative stress and whether relief of PBOO could attenuate this stress.

MATERIALS AND METHODS

Surgically created PBOO in male New Zealand white rabbits was assessed after 4 weeks in one group of rabbits (n = 4), and was relieved in two additional groups of rabbits (n = 4 each) that were assessed at 4 and 8 weeks after relief of PBOO. Four sham-operated rabbits served as controls. The assessed oxidative stress biomarkers included urinary and plasma 8-hydroxy-2'-deoxyguanosine (8-OHdG) and plasma malondialdehyde (MDA), total anti-oxidant capacity (TAC) and glutathione (GSH). In addition, the copy number of mitochondrial DNA and the 8-OHdG content in bladder tissues from these rabbits were also determined at the beginning and at indicated time points in the experiments.

RESULTS

There were significant increases in both the 8-OHdG levels of urine, plasma and bladder tissue and the plasma MDA after induction of PBOO. There were also significant decreases in the TAC, in GSH levels and in mitochondrial DNA copy number in bladder tissues after PBOO. Most importantly, all of the values returned toward the control levels after the PBOO was reversed at 8 weeks.

CONCLUSION

PBOO increases systemic and oxidative stress and its reversal results in a progressive reduction of both systemic and tissue oxidative stress.

Oxidative stress biomarkers in urine and plasma of rabbits with partial bladder outlet obstruction

What's known on the subject? and What does the study add? It has been known that there is an increase of oxidative damage in the bladder tissues of animals after PBOO. However, no reliable oxidative stress biomarkers in either urine or plasma have been available for the assessment of the severity of PBOO. This study clearly demonstrated that the levels of oxidative stress biomarkers are increased in urine and plasma of the rabbits with PBOO.

OBJECTIVE

To investigate oxidative stress and oxidative damage biomarkers in urine and plasma after partial bladder outlet obstruction (PBOO) in rabbits.

MATERIALS AND METHODS

In all, 16 male New Zealand White rabbits were separated equally into four groups: a control group and PBOO-treated groups for 2, 4 and 8 weeks. The oxidative stress biomarkers assessed included urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and plasma malondialdehyde (MDA). We also measured the total antioxidant capacity (TAC) in blood plasma. 8-OHdG, MDA and TAC were measured at both the beginning and indicated time points of the experimental design.

RESULTS

There was no significant difference in body weight among rabbits in the four groups. However, there was a significant increase in bladder weight after 2 weeks of PBOO. After 4 and 8 weeks of PBOO, there was an additional significant increase in bladder weight in all three groups. There was no difference in blood creatinine levels among the groups. In the 4- and 8-week PBOO groups, there was a significant increase of 8-OHdG in urine and of MDA in plasma, while there was a significant decrease in TAC in plasma.

CONCLUSION

The results showed that oxidative stress could be detected in the plasma and urine of rabbits after 4 and 8 weeks of PBOO, and not only from bladder tissue as previously reported. Thus, there could be an easy and alternative way to evaluate bladder function by analysis of urine and/or plasma. Additionally, rabbits with chronic PBOO showed an increase in systemic oxidative stress, which could be a novel starting point for examining the link between the lower urinary tract symptoms/benign prostate hyperplasia and metabolic syndrome in future studies.

Analysis of antioxidant activities in vegetable oils and fat soluble vitamins and biofactors by the PAO-SO method

Accumulated evidences indicate that reactive oxygen species (ROS) are involved in the pathophysiology of aging process. Antioxidants are believed to play an important role in the defense system to counteract ROS in the body. While excess hydrophilic antioxidants can be excreted easily in urine, lipophilic antioxidants can penetrate into blood lipoproteins and cell membranes, and may maintain long and high bioavailability. These lipophilic antioxidants are thus expected to contribute greatly to the prevention of age-related diseases. Oils extracted from plant seeds are known to contain various lipophilic antioxidants such as vitamin E (alpha-tocopherol) and carotenoids. They are known to not only decrease serum low-density-lipoprotein (LDL) level, but also prevent oxidation of LDL. In addition to vitamin E (alpha-tocopherol) and carotenoids, other lipophilic antioxidants such as gamma-oryzanol and sesaminol (from sesamolin) are in rice bran and sesame, respectively. They are sometimes called "vitamin-like food factors" or "biofactors." Although there are several methods for measuring the total antioxidant activities for various plant extracts, most of these methods are designed for hydrophilic antioxidants, and not for lipophilic antioxidants present in various plant seed oils. In this report, we present an assay method for the total potency of antioxidants that are soluble in oil (PAO-SO) utilizing bathocuproine (BC) as a chromogen. BC-based antioxidant activity assay shows good linearity (r(2) = 0.9986), good reproducibility (CV < 10%), and good recovery (86-91%) when dl-alpha-tocopherol, for example, is added to sesame oil. Total antioxidant activity of rape-seed oil, olive oil, and sesame oil could also be successfully measured.

Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy

In HIV-infected persons, low serum concentrations of vitamins and minerals, termed micronutrients, are associated with an increased risk of HIV disease progression and mortality. Micronutrient supplements can delay HIV disease progression and reduce mortality in HIV-positive persons not receiving highly active antiretroviral therapy (HAART). With the transition to more universal access to HAART, a better understanding of micronutrient deficiencies and the role of micronutrient supplements in HIV-positive persons receiving HAART has become a priority. The provision of simple, inexpensive micronutrient supplements as an adjunct to HAART may have several cellular and clinical benefits, such as a reduction in mitochondrial toxicity and oxidative stress and an improvement in immune reconstitution. We reviewed observational and trial evidence on micronutrients in HIV-positive persons receiving HAART to summarize the current literature and suggest future research priorities. A small number of observational studies have suggested that some, but not all, micronutrients may become replete after HAART initiation, and few intervention studies have found that certain micronutrients may be a beneficial adjunct to HAART. However, most of these studies had some major limitations, including a small sample size, a short duration of follow-up, a lack of adjustment for inflammatory markers, and an inadequate assessment of HIV-related outcomes. Therefore, few data are available to determine whether HAART ameliorates micronutrient deficiencies or to recommend or refute the benefit of providing micronutrient supplements to HIV-positive persons receiving HAART. Because micronutrient supplementation may cause harm, randomized placebo-controlled trials are needed. Future research should determine whether HAART initiation restores micronutrient concentrations, independent of inflammatory markers, and whether micronutrient supplements affect HIV-related outcomes in HIV-positive persons receiving HAART.

Selenium levels in relation to morbidity and mortality among children born to HIV-infected mothers

OBJECTIVE

To examine the relation between selenium status and child mortality and morbidity among children born to HIV-infected mothers.

DESIGN

Prospective cohort study.

METHODS

Study participants were originally part of a trial to study the effect of maternal vitamin supplements on maternal and child health outcomes. Morbidity information was collected during monthly clinic visits until the child reached 24 months of age. Out of 984 livebirths, 806 had morbidity information, and 610 also had data on plasma selenium levels available.

SETTING

A study clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania, a tertiary-care hospital.

RESULTS

The median age at baseline was 10.5 weeks. A total of 117 (19%) of the 610 study children died during follow-up. In a multivariate model, child plasma selenium levels were inversely associated with risk of all-cause mortality (P-value, test for trend=0.05). Plasma selenium levels were not significantly associated with risk of diarrhea or respiratory outcomes.

CONCLUSIONS

Among infants born to HIV-infected women in sub-Saharan Africa, selenium status may be important to prevent child mortality. These preliminary findings warrant future reexamination.

Long-term experience with combination antiretroviral therapy that contains nelfinavir for up to 7 years in a pediatric cohort

OBJECTIVE

We sought to provide long-term data on the clinical, immunologic, and virologic response to highly active antiretroviral therapy in infants and children who are naive to protease inhibitors.

METHODS

HIV-1-infected children who were naive to protease inhibitors were treated with a combination of nelfinavir and 2 nucleoside reverse transcriptase inhibitors (stavudine and lamivudine) in an observational, prospective, single-center study. Virologic failure-free survival was assessed by Kaplan-Meier analyses. The increase in CD4+ T cells during follow-up was estimated with a generalized linear model incorporating repeated measurements.

RESULTS

Thirty-nine HIV-1-infected children were included and followed for a median period of 227 weeks (interquartile range: 108-275 weeks). The virologic failure-free survival rate was 74%, 66%, 58%, and 54% after 48, 96, 144, and 240 weeks, respectively. Children who experienced virologic failure in 48 weeks (or 96 weeks) were younger at baseline compared with the responders (0.8 vs 5.3 years). Eighteen children remained on the regimen for >5 years. All children, including the nonresponders, showed a sustained immunologic response. Grades 3 to 4 toxicity was observed in 2 patients only. Eleven developed clinically evident lipodystrophy.

CONCLUSION

Combination therapy can be used safely in infants and children over a long period. Young age is strongly associated with virologic failure. Although the virologic response declined, immunologic parameters and clinical improvement were sustained up to 7 years, at the expense of lipodystrophy.

HIV-1 antiviral activity of recombinant natural killer cell enhancing factors, NKEF-A and NKEF-B, members of the peroxiredoxin family

CD8(+) T-cells are a major source for the production of non-cytolytic factors that inhibit HIV-1 replication. In order to characterize further these factors, we analyzed gene expression profiles of activated CD8(+) T-cells using a human cDNA expression array containing 588 human cDNAs. mRNA for the chemokine I-309 (CCL1), the cytokines granulocyte-macrophage colony-stimulating factor and interleukin-13, and natural killer cell enhancing factors (NKEF) -A and -B were up-regulated in bulk CD8(+) T-cells from HIV-1 seropositive individuals compared with seronegative individuals. Recombinant NKEF-A and NKEF-B inhibited HIV-1 replication when exogenously added to acutely infected T-cells at an ID(50) (dose inhibiting HIV-1 replication by 50%) of approximately 130 nm (3 microg/ml). Additionally, inhibition against dual-tropic simian immunodeficiency virus and dual-tropic simian-human immunodeficiency virus was found. T-cells transfected with NKEF-A or NKEF-B cDNA were able to inhibit 80-98% HIV-1 replication in vitro. Elevated plasma levels of both NKEF-A and NKEF-B proteins were detected in 23% of HIV-infected non-treated individuals but not in persons treated with highly active antiviral therapy or uninfected persons. These results indicate that the peroxiredoxin family members NKEF-A and NKEF-B are up-regulated in activated CD8(+) T-cells in HIV infection, and suggest that these antioxidant proteins contribute to the antiviral activity of CD8(+) T-cells.