ARHGDIA mutations cause nephrotic syndrome via defective RHO GTPase signaling

Nephrotic syndrome (NS) is divided into steroid-sensitive (SSNS) and -resistant (SRNS) variants. SRNS causes end-stage kidney disease, which cannot be cured. While the disease mechanisms of NS are not well understood, genetic mapping studies suggest a multitude of unknown single-gene causes. We combined homozygosity mapping with whole-exome resequencing and identified an ARHGDIA mutation that causes SRNS. We demonstrated that ARHGDIA is in a complex with RHO GTPases and is prominently expressed in podocytes of rat glomeruli. ARHGDIA mutations (R120X and G173V) from individuals with SRNS abrogated interaction with RHO GTPases and increased active GTP-bound RAC1 and CDC42, but not RHOA, indicating that RAC1 and CDC42 are more relevant to the pathogenesis of this SRNS variant than RHOA. Moreover, the mutations enhanced migration of cultured human podocytes; however, enhanced migration was reversed by treatment with RAC1 inhibitors. The nephrotic phenotype was recapitulated in arhgdia-deficient zebrafish. RAC1 inhibitors were partially effective in ameliorating arhgdia-associated defects. These findings identify a single-gene cause of NS and reveal that RHO GTPase signaling is a pathogenic mediator of SRNS.     

Utility of 99mTc-labelled antimicrobial peptide ubiquicidin (29-41) in the diagnosis of diabetic foot infection

Purpose

Detection of osteomyelitis beneath a diabetic foot ulcer is imperative for proper management; however, accurate and noninvasive diagnosis of osteomyelitis remains a challenge. Ubiquicidin 29-41 (UBI 29-41) is a synthetic antimicrobial peptide fragment reported to be highly infection-specific. ^99mTc-UBI 29-41 has recently been reported to be a promising radiotracer for infection imaging. The aim of this prospective study was to evaluate the utility of ^99mTc-UBI 29-41 scintigraphy in diabetic patients with suspected osteomyelitis of the foot.

Methods

Included in the study were 65 patients with type 2 diabetes mellitus and foot ulcer and with clinical suspicion of osteomyelitis . Each patient had a three-phase bone scan and a ^99mTc-UBI scan at 30 and 60 min after injection. The scan was considered to be consistent with osteomyelitis when the ^99mTc-UBI 29-41 uptake was concordant with the ^99mTc-MDP uptake. It was considered negative for osteomyelitis if there was no uptake of ^99mTc-UBI 29-41 or if ^99mTc-UBI 29-41 accumulated in an area not concordant with the abnormal uptake of ^99mTc-MDP on the bone scan. In the latter case a diagnosis of soft-tissue infection was made. Bone infection was confirmed by bone biopsy/culture and by clinical and radiological follow-up.

Results

Final analysis was done in 55 patients. Osteomyelitis was confirmed in 37 patients, and 18 patients were free of bone infection. ^99mTc-UBI 29-41 was positive in all 37 patients and with the bone scan as the reference for the bone identified all osteomyelitic foci (68 in total). ^99mTc-UBI 29-41 was negative for osteomyelitis in all 18 patients, and 17 of these patients were diagnosed with soft-tissue infection (^99mTc-UBI 29-41 accumulation without concordant abnormal uptake on bone scintigraphy). The sensitivity, specificity and accuracy of ^99mTc-UBI 29-41 scan in combination with three-phase bone scan for the diagnosis of osteomyelitis in diabetic foot was 100 %. Accuracy for soft-tissue infection was also 100 %. Maximum accumulation of the ^99mTc-UBI 29-41 with maximum target to background activity was observed in the infectious foci at 30 min after injection.

Conclusion

Tc-UBI 29-41 may be a useful agent for the accurate diagnosis of bone infection in diabetic foot because of the high accuracy demonstrated in this pilot study. It was able to differentiate between bone and soft-tissue involvement effectively in combination with a bone scan.     

FSWs Typology and Condoms Use Among HIV High Risk Groups in Sindh,Pakistan: A Developing Country Perspective

Objective

We aimed to determine the association of FSWs typology with condom use among HIV high risk groups in Sindh, Pakistan

Introduction

HIV is growing rapidly worldwide resulting in estimated 34 million population [1]. Recently, its epidemic has spread in Africa, Latin America, and the Caribbean, and most parts of Asia [2]. According to Antenatal sero surveillance study conducted in 2011 by Agriteam canada, it’s prevalence in Pakistan is <0.1 [3].Focusing narrowly, its prevalence in Sindh, (one of the provinces of Pakistan) is similar in general population, but it is in the phase of concentrated epidemic (having more than 5% of prevalence in high risk groups)in vulnerable groups like IDUs and Male sex workers and transgender [4].Sexual intercourse has been identified as major route especially in HIV high risk groups including male sex workers, female sex workers (FSWs), transgender (hijras) and IV drug users. Among them, FSWs are at high risk because of unprotected sex and illicit drug use. Their prevalence is found to be 30.7% in low and middle income countries [5]. South Asia contributed with 12.63 lakh FSW in India only [6]. On the basis of their station of work, they are categorized into facility based (kothikhana, brothel or home) and mobile (street, mobile or beggars). They use different preventive measures including condom for their protection from HIV [7]. It varies with availability and access [8] . FSWs typology have different cliental and mode of action, therefore, it important to explore the preventive methods.

Methods

Data was extracted from Second Generation Surveillance, Integrated behavioral and biological survey, Round IV for HIV infection conducted by Agriteam Canada in partnership with National AIDS Control Program, Pakistan in 2011. It was a cross sectional survey for high risk groups including FSWs from Pakistan. It was ethically approved by Review Board of the Public Health Agency of Canada and HOPE International’s Ethical Review Board, Pakistan. From Sindh province, FSWs based in Karachi, Sukkur and Larkana were recruited. Considering typology, they were categorized as mobile or facility based. After informed consent, socio-demographic and risk behavior were inquired. HIV was tested by ELISA/EIA and confirmed by Western Blot. Data was analyzed on SPSS 19. Continuous variables were expressed as mean±SD while categorical as frequency(%). Logistic regression assessed the association of FSWs typology with condoms use among HIV high risk groups.

Results

Out of 4567 high risk population, 1127 were identified as FSWs. Mean age was 26.9 years. Most of them were facility based (72.8%) and 81.3% used condoms. Typology, age, education, duration of involvement, number of client per day, number of paid oral sex per month, knowledge about STI and knowledge about drop in center were significantly associated with condom use among HIV high risk groups.

Conclusions

Majority of facility based FSWs use condoms to prevent HIV infection. Awareness and access to home based FSWs should be increased. It may help in targeting and designing preventive strategies for them at government and mass level.     

Misoprostol for term labor induction: a randomized controlled trial

ObjectivesThe aim of this study was to compare the efficacy of vaginal misoprostol with vaginal dinoprostone for term labor induction.Material and MethodsIt was a randomized controlled trial done in the Obstetrics Department, Shifa Community Health Centre, Shifa International Hospital (Teaching Hospital of Shifa College of Medicine, Islamabad). All pregnant women at term pregnancy coming for induction of labor were enrolled. 246 women fulfilled the inclusion criteria. Out of them 208 women consented to be part of the study. These women were then randomized to receive either Treatment A (vaginal misoprostol) or Treatment B (vaginal dinoprostone). Data were completed for 200 women. These included induction labor and induction-delivery interval, fetal and maternal complications, and baby apgar score.ResultsOut of 200 women in the study, 100 were in Group A and 100 in Group B. Labor commenced in a mean of 6.67 hours (±3.63) in Group A whereas it took a mean of 8.41 hours (±5.13) in Group B (p = 0.00). Actual induction to delivery (of the baby) interval was a mean of 11.68 hours (±4.55) for misoprostol and 15.37 hours (±5.30) for dinoprostone group (p = 0.00). There were no cases of uterine rupture in both groups; however, there were 10 cases of uterine hyperstimulation in Group A and 4 in Group B (p = 0.09).ConclusionsIt is time to re-evaluate the role of misoprostol for term labor induction. It is an efficacious and cost-effective alternative to the presently licensed treatment.     

Accuracy of the Safer Dx Instrument to Identify Diagnostic Errors in Primary Care

IMPORTANCE

Diagnostic errors are common and harmful, but difficult to define and measure. Measurement of diagnostic errors often depends on retrospective medical record reviews, frequently resulting in reviewer disagreement.

OBJECTIVES

We aimed to test the accuracy of an instrument to help detect presence or absence of diagnostic error through record reviews.

DESIGN

We gathered questions from several previously used instruments for diagnostic error measurement, then developed and refined our instrument. We tested the accuracy of the instrument against a sample of patient records (n?=?389), with and without previously identified diagnostic errors (n?=?129 and n?=?260, respectively).

RESULTS

The final version of our instrument (titled Safer Dx Instrument) consisted of 11 questions assessing diagnostic processes in the patient–provider encounter and a main outcome question to determine diagnostic error. In comparison with the previous sample, the instrument yielded an overall accuracy of 84 %, sensitivity of 71 %, specificity of 90 %, negative predictive value of 86 %, and positive predictive value of 78 %. All 11 items correlated significantly with the instrument’s error outcome question (all p values?≤?0.01). Using factor analysis, the 11 questions clustered into two domains with high internal consistency (initial diagnostic assessment, and performance and interpretation of diagnostic tests) and a patient factor domain with low internal consistency (Cronbach’s alpha coefficients 0.93, 0.92, and 0.38, respectively).

CONCLUSIONS

The Safer Dx Instrument helps quantify the likelihood of diagnostic error in primary care visits, achieving a high degree of accuracy for measuring their presence or absence. This instrument could be useful to identify high-risk cases for further study and quality improvement.

     

Anti-arthritic effect of GN1, a novel synthetic analog of glucosamine,in the collagen-induced arthritis model in rats

Objective  

Glucosamine is a naturally occurring amino monosaccharide that maintains the elasticity and strength of the cartilage tissues. It has been used to treat osteoarthritis in humans; however, in severe conditions of inflammation and pain, glucosamine alone is not enough, and it is important to improve its biological activity. Our research group has recently taken an interest in the synthetic manipulation of amino sugars to develop some efficient pharmacophores, e.g., β-d-glucosamine, to combat rheumatoid arthritis, and tested its anti-arthritic effects in the collagen-induced arthritis (CIA) model in rats.     

COQ6 mutations in human patients produce nephrotic syndrome with sensorineural deafness

Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of end-stage renal failure. Identification of single-gene causes of SRNS has generated some insights into its pathogenesis; however, additional genes and disease mechanisms remain obscure, and SRNS continues to be treatment refractory. Here we have identified 6 different mutations in coenzyme Q10 biosynthesis monooxygenase 6 (COQ6) in 13 individuals from 7 families by homozygosity mapping. Each mutation was linked to early-onset SRNS with sensorineural deafness. The deleterious effects of these human COQ6 mutations were validated by their lack of complementation in coq6-deficient yeast. Furthermore, knockdown of Coq6 in podocyte cell lines and coq6 in zebrafish embryos caused apoptosis that was partially reversed by coenzyme Q10 treatment. In rats, COQ6 was located within cell processes and the Golgi apparatus of renal glomerular podocytes and in stria vascularis cells of the inner ear, consistent with an oto-renal disease phenotype. These data suggest that coenzyme Q10-related forms of SRNS and hearing loss can be molecularly identified and potentially treated.