Mutational analysis of the CYP1B1 gene in Pakistani primary congenital glaucoma patients: Identification of four known and a novel causative variant at the 3′ splice acceptor site of intron 2

Primary congenital glaucoma (PCG) causes blindness in early age. It has an autosomal recessive pattern of inheritance, hence is more prevalent in populations with frequent consanguineous marriages that occur in the Pakistani population. Mutations in the CYP1B1 gene are commonly associated with PCG. The aim of the present study was to identify genetic mutations in the CYP1B1 gene in PCG cases belonging to 38 Pakistani families. DNA was extracted using blood samples collected from all enrolled patients, their available unaffected family members and controls. Direct sequencing of the CYP1B1 gene revealed a novel 3' splice acceptor site causative variant segregating in an autosomal recessive manner in a large consanguineous family with four PCG‐affected individuals. The novel variant was not detected in 93 ethnically matched controls. Furthermore, four already reported mutations, including p.G61E, p.R355X, p.R368H, and p.R390H were also detected in patients belonging to nine different families. All identified causative variants were evaluated by computational programs, that is, SIFT, PolyPhen‐2, and MutationTaster. Pathogenicity of the novel splice site variant identified in this study was analyzed by Human Splicing Finder and MaxEntScan. Ten out of 38 families with PCG had the disease due to CYP1B1 mutations, suggesting CYP1B1 was contributing to PCG in these Pakistani patients. Identification of this novel 3' splice acceptor site variant in intron 2 is the first report for the CYP1B1 gene contributing to genetic heterogeneity of disease.     

Genetic polymorphism of Y-chromosomal STRs in Gujjar population of Punjab

Y-STR polymorphism of Gujjar population was determined by using AmpFISTR®YfilerTM PCR amplification kit. A total 176 haplotypes were obtained after the analysis of 17 Y-STR loci in 176 genetically unrelated individuals. Haplotype diversity and discrimination capacity attained was 0.99730 and 0.652201325, respectively. The comparison of Gujjar population with 16 other populations revealed that Gujjars have low genetic distance from Punjabi, Sindhi, and Pakhtun population of Pakistan; Azad Kashmir, Saraswat Brahmin from India; Bangladeshi population; north and south of Afghanistan; and Uttar Pradesh India which hints toward the migrational route Gujjars took over the centuries. This data is of significant value for population studies and forensic applications.     

Evaluation of Bremsstrahlung radiation dose in stereotactically radiocolloid therapy of cystic craniopharyngioma tumors with <Superscript>32</Superscript>P radio-colloid

Over 90% of craniopharyngeal brain tumors are cystic, which enables the injection of beta emitters such as phosphorus-32 (³²P) radio-colloid into cysts for their treatment. The aim of this study was to evaluate the clinical and theoretical modelling of Bremsstrahlung radiation dose resulting from stereotactic radio-colloid therapy of cystic craniopharyngioma tumors with ³²P. ³²P radio-colloid with appropriate activity concentration was injected to a head phantom, and then the Bremsstrahlung radiation spectrum and planar images were obtained using a gamma camera. Both phantom and gamma camera were simulated using MCNPX code, and the results were compared with practical results. Bremsstrahlung radiation spectrum was measured using a handheld gamma spectrometer for two patients treated with stereotactic radio-colloid therapy with ³²P in different positions and compared to Monte Carlo simulation. Results of counting and determining sensitivity coefficients in the air and the attenuating environment were obtained. Also, comparing the counting sensitivity from practical and simulation methods indicated the agreement of the data between the two methods. Comparison of the spectra from different positions around patient’s head indicated the ability to use this detector to quantify the activity in the operating room. Selection of the spectrum is important in Bremsstrahlung radiation imaging. We can take advantage of spectrometry measurement using gamma camera, handheld gamma spectrometer for patient, and theoretical modeling with Monte Carlo code to evaluate radiopharmaceutical distribution, leakage, as well as estimate activity and predict therapeutic effects in other adjacent structures and ultimately optimize radio-colloid therapy in cystic craniopharyngeal patients.     

Exploring the mechanistic insights of Cas scaffolding protein family member 4 with protein tyrosine kinase 2 in Alzheimer’s disease by evaluating protein interactions through molecular docking and dynamic simulations

Cas scaffolding protein family member 4 and protein tyrosine kinase 2 are signaling proteins, which are involved in neuritic plaques burden, neurofibrillary tangles, and disruption of synaptic connections in Alzheimer’s disease. In the current study, a computational approach was employed to explore the active binding sites of Cas scaffolding protein family member 4 and protein tyrosine kinase 2 proteins and their significant role in the activation of downstream signaling pathways. Sequential and structural analyses were performed on Cas scaffolding protein family member 4 and protein tyrosine kinase 2 to identify their core active binding sites. Molecular docking servers were used to predict the common interacting residues in both Cas scaffolding protein family member 4 and protein tyrosine kinase 2 and their involvement in Alzheimer’s disease-mediated pathways. Furthermore, the results from molecular dynamic simulation experiment show the stability of targeted proteins. In addition, the generated root mean square deviations and fluctuations, solvent-accessible surface area, and gyration graphs also depict their backbone stability and compactness, respectively. A better understanding of CAS and their interconnected protein signaling cascade may help provide a treatment for Alzheimer’s disease. Further, Cas scaffolding protein family member 4 could be used as a novel target for the treatment of Alzheimer’s disease by inhibiting the protein tyrosine kinase 2 pathway.     

Computed tomography-guided stereotactic biopsy of intracranial lesions in pediatric patients

Purpose  

The primary objective of this study was to report the results of author’s 18-year experience of diagnostic stereotactic biopsy procedures in children with intracranial lesions.     

Systemic juvenile xanthogranuloma with multiple central nervous system lesions

Juvenile xanthogranulomatosis (JXG) is an uncommon histiocytic disorder that is usually benign and limited to the skin. The systemic form of JXG is rare and may be associated with severe morbidity and mortality especially in central nervous system (CNS) involvement. Here, we describe a six-year-old boy with disseminated skin lesions and neurological signs and symptoms. Diagnostic work up revealed multiple brain lesions. A skin biopsy and a stereotactic brain biopsy considered suggestive of systemic JXG. Treatment with prednisolone, vinblastine and methotrexate was successful with regression of skin and CNS lesions. The patient has been in remission for almost three years.     

Designing and validation of a Hindi-language parent self-report developmental screening tool

Aim

To design and validate Hindi-language parent self-report developmental screening questionnaires for 9-month and 18-month-old Indian children.

Design

Cross-sectional study

Setting

Tertiary-care pediatric hospital from April 2014 to March 2016

Participants

In each age group (9-month and 18-month), 45 children were enrolled for designing of questionnaires (30 for obtaining parental observations of current development and 15 for pre-testing). For validation of tool, 100 children (60 low risk and 40 high risk) were enrolled in each age group.

Methods

For designing, observations regarding current developmental milestones were obtained from parents and a list of all enumerated milestones was prepared. After detailed discussion by a team of developmental pediatricians, pediatric resident, clinical psychologist and language specialist, milestones were chosen for drafting of questionnaires. In each age group, drafts were pre-tested and required modifications were done. The final questionnaires contained 20 items each to be scored on a Likert scale (total score ranging from 20 to 60, a lower score indicating a higher risk of developmental delay). These questionnaires were validated against Developmental Assessment Scale for Indian Infants (DASII), a gold standard instrument.

Results

On ROC analysis, the 9-month and 18-month screening tool had area under curve of 0.988 and 0.953, respectively, for detecting developmental delay. Score ≤50 on the 9-months questionnaire had sensitivity of 100% and specificity of 87.2%. Score ≤49 on the 18-months questionnaire had sensitivity of 91.4% and specificity of 88.7%.

Conclusions

The new questionnaires have a promising role in developmental screening of children at the time of routine immunizations in our country.

     

Novel prism shaped C3N4-doped Fe@Co3O4 nanocomposites and their dye degradation and bactericidal potential with molecular docking study

Novel prism shaped C₃N₄-doped Fe@Co₃O₄ nanocomposites were fabricated via a co-precipitation route for effective removal of organic pollutants from water and for bactericidal applications. Doping of C₃N₄ in the heterojunction significantly enhanced the photocatalytic and sonocatalytic activity against methylene blue ciprofloxacin (MBCF) dye. The main purpose of doping Fe atoms in the cobalt lattice was to generate crystal and surface defects. Moreover, the optimum doping amount of C₃N₄ for maximum degradation performance was evaluated. A detailed examination of the prepared nanocomposites was carried out systematically using various characterization tools for better understanding. HR-TEM images revealed the formation of novel prism shaped structures that exhibited outstanding degradation of the organic dye in water. Significant bactericidal potential was also observed for the synthesized nanocomposites against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. In silico, molecular docking studies against β-lactamase, DHFR and FabI enzymes served to elucidate the mechanism governing the bactericidal activity of the as-synthesized nanoparticles (NPs). Furthermore, a scavenging study by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and COD (chemical oxygen demand) analysis was performed in order to evaluate active species and the anti-oxidant potential of prepared composites.

This study provides new insights into the use of cobalt-based heterojunction photocatalysts for dye degradation and antibacterial applications (a) synthesis mechanism of C₃N₄ (b) schematic of synthesis route adopted for fabrication of nanocomposites.