Effects of triple antioxidant therapy on measures of cardiovascular autonomic neuropathy and on myocardial blood flow in type 1 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

We evaluated the effects of a combination triple antioxidant therapy on measures of cardiovascular autonomic neuropathy (CAN) and myocardial blood flow (MBF) in patients with type 1 diabetes.

METHODS

This was a randomised, parallel, placebo-controlled trial. Participants were allocated to interventions by sequentially numbered, opaque, sealed envelopes provided to the research pharmacist. All participants and examiners were masked to treatment allocation. Participants were evaluated by cardiovascular autonomic reflex testing, positron emission tomography with [(11)C]meta-hydroxyephedrine ([(11)C]HED) and [(13)N]ammonia, and adenosine stress testing. Markers of oxidative stress included 24 h urinary F2-isoprostanes. Diabetic peripheral neuropathy (DPN) was evaluated by symptoms, signs, electrophysiology and intra-epidermal nerve fibre density. Randomised participants included 44 eligible adults with type 1 diabetes and mild-to-moderate CAN, who were aged 46 ± 11 years and had HbA1c 58 ± 5 mmol/mol (7.5 ± 1.0%), with no evidence of ischaemic heart disease. Participants underwent a 24-month intervention, consisting of antioxidant treatment with allopurinol, α-lipoic acid and nicotinamide, or placebo. The main outcome was change in the global [(11)C]HED retention index (RI) at 24 months in participants on the active drug compared with those on placebo.

RESULTS

We analysed data from 44 participants (22 per group). After adjusting for age, sex and in-trial HbA1c, the antioxidant regimen was associated with a slight, but significant worsening of the global [(11)C]HED left ventricle RI (-0.010 [95% CI -0.020, -0.001] p = 0.045) compared with placebo. There were no significant differences at follow-up between antioxidant treatment and placebo in the global MBF, coronary flow reserve, or in measures of DPN and markers of oxidative stress. The majority of adverse events were of mild-to-moderate severity and did not differ between groups

CONCLUSIONS/INTERPRETATION

In this cohort of type 1 diabetes patients with mild-to-moderate CAN, a combination antioxidant treatment regimen did not prevent progression of CAN, had no beneficial effects on myocardial perfusion or DPN, and may have been detrimental. However, a larger study is necessary to assess the underlying causes of these findings.

Microstructure and homogeneity of distribution of mineralised struts determine callus strength

Non-invasive assessment of fracture healing, both in clinical and animal studies, has gained favour as surrogate measure to estimate regain of mechanical function. Micro-computed tomography (µCT) parameters such as fracture callus volume and mineralisation have been used to estimate callus mechanical competence. However, no in-depth information has been reported on microstructural parameters in estimating callus mechanical competence. The goal of this study is to use differently conditioned mice exhibiting good and impaired fracture healing outcomes and investigate the relationship between µCT imaging parameters (volume, mineralisation, and microstructure) that best estimate the callus strength and stiffness as it develops over time. A total of 99 mice with femoral fracture and intramedullary stabilisation were divided into four groups according to conditioning: wild type, NF1 knock-out, RAG1 knock-out and macrophage depleted. Animals were sacrificed at 14, 21, 28 or 35 days and µCT parameters and torsional stiffness and strength were assessed post-sacrifice. Using linear regression for all groups and time points together, torsional stiffness could be estimated with strut thickness, strut number and strut homogeneity (R² = 0.546, p < 0.0001); torsional strength could be estimated using bone mineral density, strut thickness and strut homogeneity (R² = 0.568, p < 0.0001). Differently conditioned mice that result in different fracture healing outcomes have been shown to result in varying structural, material and volumetric µCT parameters which can be used to estimate regain of bone strength. This study is the first to demonstrate that microstructure and strut homogeneity influence callus stiffness and strength.

Perceptions regarding barriers and facilitators to combination antiretroviral therapy adherence among people living with HIV/AIDS in Gujarat, India: A qualitative study

OBJECTIVES

To know the perceptions regarding barriers and facilitators to cART adherence among people living with HIV/AIDS MATERIALS AND METHODS: To adapt U.S. based SAFETALK "prevention with positives" intervention to be culturally relevant in Gujarat, India in assisting PLWHA, a formative study was conducted. We conducted 30 in-depth interviews with PLWHA in the local language, assessing the experiences, perceived barriers, and facilitators to combination antiretroviral therapy (cART) among PLWHA in Gujarat. PLWHA were selected from the Voluntary Counseling and Testing Centre (VCTC) in Gujarat. To triangulate interview findings, we conducted two focus group discussions (FGDs) with medical and non-medical providers, respectively.

RESULTS

Travel and commuting to clinic, fear of possible physical reactions, high cost of ART from private practitioners, CD4 count being in normal limits and resistance to medication acted as barriers to cART adherence. Initiation of cART was facilitated by family members' suggestion, advice of treating doctors and counselors, appropriate counseling before starting cART, belief that cART would aid in living a better and longer life and due to lowering of the CD4 count.

INTERPRETATION AND CONCLUSIONS

Our study suggests that several issues need to be considered when providing cART. Further research is needed to study interactions between patients and their health care providers.

Mycobacterium tuberculosis WhiB4 regulates oxidative stress response to modulate survival and dissemination in vivo

Host-generated oxidative stress is considered one of the main mechanisms constraining Mycobacterium tuberculosis (Mtb) growth. The redox-sensing mechanisms in Mtb are not completely understood. Here we show that WhiB4 responds to oxygen (O₂) and nitric oxide (NO) via its 4Fe-4S cluster and controls the oxidative stress response in Mtb. The WhiB4 mutant (MtbΔwhiB4) displayed an altered redox balance and a reduced membrane potential. Microarray analysis demonstrated that MtbΔwhiB4 overexpresses the antioxidant systems including alkyl hydroperoxidase (ahpC-ahpD) and rubredoxins (rubA-rubB). DNA binding assays showed that WhiB4 [4Fe-4S] cluster is dispensable for DNA binding. However, oxidation of the apo-WhiB4 Cys thiols induced disulphide-linked oligomerization, DNA binding and transcriptional repression, whereas reduction reversed the effect. Furthermore, WhiB4 binds DNA with a preference for GC-rich sequences. Expression analysis showed that oxidative stress repressed whiB4 and induced antioxidants in Mtb, while their hyper-induction was observed in MtbΔwhiB4. MtbΔwhiB4 showed increased resistance to oxidative stress in vitro and enhanced survival inside the macrophages. Lastly, MtbΔwhiB4 displayed hypervirulence in the lungs of guinea pigs, but showed a defect in dissemination to their spleen. These findings suggest that WhiB4 systematically calibrates the activation of oxidative stress response in Mtb to maintain redox balance, and to modulate virulence.

HIV serostatus disclosure: Experiences and perceptions of people living with HIV/AIDS and their service providers in Gujarat, India

BACKGROUND

Human immunodeficiency virus (HIV) disclosure offers important benefits to people living with HIV/AIDS. However, fear of discrimination, blame, and disruption of family relationships can make disclosure a difficult decision. Barriers to HIV disclosure are influenced by the particular culture within which the individuals live. Although many studies have assessed such barriers in the U.S., very few studies have explored the factors that facilitate or prevent HIV disclosure in India. Understanding these factors is critical to the refinement, development, and implementation of a counseling intervention to facilitate disclosure.

MATERIALS AND METHODS

To explore these factors, we conducted 30 in-depth interviews in the local language with HIV- positive individuals from the Integrated Counselling and Testing Centre in Gujarat, India, assessing the experiences, perceived barriers, and facilitators to disclosure. To triangulate the findings, we conducted two focus group discussions with HIV medical and non-medical service providers, respectively.

RESULTS

Perceived HIV-associated stigma, fear of discrimination, and fear of family breakdown acted as barriers to HIV disclosure. Most people living with HIV/AIDS came to know of their HIV status due to poor physical health, spousal HIV-positive status, or a positive HIV test during pregnancy. Some wives only learned of their husbands' HIV positive status after their husbands died. The focus group participants confirmed similar findings. Disclosure had serious implications for individuals living with HIV, such as divorce, maltreatment, ostracism, and decisions regarding child bearing.

INTERPRETATION AND CONCLUSION

The identified barriers and facilitators in the present study can be used to augment training of HIV service providers working in voluntary counseling and testing centers in India.

Retinoblastoma

Retinoblastoma is the most common intraocular malignancy in children and one of the very few life-threatening ophthalmic conditions. Genetically, the disease may be heritable or non-heritable. It can have unilateral or bilateral involvement and can present either sporadically or with a positive family history. Leukocoria and strabismus are the most common presentations. Diagnosis is made by indirect ophthalmoscopy aided by imaging techniques. Multidisciplinary management is aimed at saving lives, salvaging the globe and maintaining good vision. The use of neoadjuvant chemotherapy and focal treatments, such as cryotherapy, laser photocoagulation, transpupillary thermotherapy, brachytherapy and periocular chemotherapy, form the mainstay of globe preserving treatment in retinoblastoma. In developing countries, retinoblastoma is unfortunately accompanied by a high mortality rate due to delayed diagnosis made at advanced stages of the disease. Early diagnosis and timely management are vital for a good prognosis.

Perceptions regarding barriers and facilitators to combination antiretroviral therapy adherence among people living with HIV/AIDS in Gujarat, India: A qualitative study

OBJECTIVES

To know the perceptions regarding barriers and facilitators to cART adherence among people living with HIV/AIDS MATERIALS AND METHODS: To adapt U.S. based SAFETALK "prevention with positives" intervention to be culturally relevant in Gujarat, India in assisting PLWHA, a formative study was conducted. We conducted 30 in-depth interviews with PLWHA in the local language, assessing the experiences, perceived barriers, and facilitators to combination antiretroviral therapy (cART) among PLWHA in Gujarat. PLWHA were selected from the Voluntary Counseling and Testing Centre (VCTC) in Gujarat. To triangulate interview findings, we conducted two focus group discussions (FGDs) with medical and non-medical providers, respectively.

RESULTS

Travel and commuting to clinic, fear of possible physical reactions, high cost of ART from private practitioners, CD4 count being in normal limits and resistance to medication acted as barriers to cART adherence. Initiation of cART was facilitated by family members' suggestion, advice of treating doctors and counselors, appropriate counseling before starting cART, belief that cART would aid in living a better and longer life and due to lowering of the CD4 count.

INTERPRETATION AND CONCLUSIONS

Our study suggests that several issues need to be considered when providing cART. Further research is needed to study interactions between patients and their health care providers.