Basan syndrome in a family from South India: a novel SMARCAD1 variant

Basan syndrome is a rare ectodermal dysplasia characterized by a triad of adermatoglyphia, reticulate pigmentation and nail dystrophy, in addition to transient neonatal findings of acral blistering and facial milia. The genetic basis was recently established to be heterozygous mutations affecting the skin-specific isoform of SMARCAD1. It is now considered part of the spectrum of disorders resulting from haploinsufficiency of this isoform, which includes both Huriez syndrome and autosomal dominant adermatoglyphia. Here, we describe a family with Basan syndrome from South India with a novel SMARCAD1 variant (c.378+1delGTAA) affecting the known mutational hotspot in exon 1.

Mitigation of harmonics and unbalanced source voltage condition in standalone microgrid: positive sequence component and dynamic phasor based compensator with real-time approach

Penetration of Distributed Energy Resources (DER) is in high demand to supply power to the load where the grid is not available. Many of these sources are a single phase source used to form standalone Microgrid (MG). Single phase connectivity of these sources results in an unbalanced source voltage condition (UbSVC). Interfacing power electronic devices also inject the harmonics into Point of Common Coupling (PCC) voltage. The effect of this unbalance and harmonics on the operation of standalone MG is analysed in this paper in a twofold manner. One at a reduced power transfer from DER to load and the other is an error produced in Phase Locked Loop (PLL) operation. Positive Sequence Component (PSC) based and Dynamic Phasor (DP) based compensation techniques are proposed in this paper to mitigate the effect of UbSVC. Simulation validates that both the proposed methods are capable to provide balanced load voltage condition under UbSVC in terms of Voltage Unbalance Factor (VUbF). It also enhances the power transferred from DER to load during an UbSVC. The performance of the proposed compensator during UbSVC and harmonic presence is validated in real-time simulation using Opal-RT and dSPACE simulators.

Evaluation of tear film stability before and after laser in situ keratomileusis

OBJECTIVE

The study was conducted to evaluate tear film stability and tear secretion before and after laser in situ keratomileusis.

MATERIALS AND METHODS

It was a prospective, longitudinal and non-comparative analysis of clinical data of 20 consecutive myopic patients (40 eyes) collected before and after laser in situ keratomileusis. Assessments included tear secretion (Schirmer I and II), fluorescein tear break up time and ocular surface staining.

STATISTICS

The statistical package for social science (SPSS 10.0) was used for data analysis. The parameters of tear secretion and tear stability were analyzed using the paired and unpaired Student t-tests.

RESULTS

Schirmer II was reduced at seven days (9.5 ± 4.30 mm) and one month (10.3 ± 3.06 mm, p=0.001) after operation from the pre-operative value of 16.12 ± 3.90 mm. Tear film stability significantly decreased at seven days (6.79 ± 3.05 sec, p Less than 0.001) and one month (8.03 ± 2.81secs, p less than 0.001) from its pre-operative value (12.68 ± 2.69 secs). 87.5% had tear film instability (FBUT less than 10secs) seven days after surgery; it was reduced to 75 % at one month and 27.5 % at three months. It was 7.5 % before surgery. Corneal staining score was increased significantly at seven days (1.42 ± 1. 58, p less than 0.01) and one month (0.95 ± 1.41, p=0.02), from the pre-operative score of 0.17 ± 0.44.

CONCLUSION

Laser in situ keratomileusis significantly alters the tear film stability, Schirmer values and corneal staining at least for three months.

Practice patterns of neurology in India: fewer hands, more work

BACKGROUND

India is a populous country housing over a billion people. Neurology as a specialty is being practiced in India for over 50 years but the number of physicians devoted to fulltime neurology is limited. This fact coupled with the privatized healthcare system and limited infrastructure has led to situations different from the more developed healthcare systems.

AIM

To study the practice patterns of neurology in India.

SETTING AND DESIGN

Questionnaire-based study.

MATERIALS AND METHODS

Questionnaire was sent to 250 members of the Indian Academy of Neurology [sample size approximately 25%] using random number table. The responses were tabulated and analyzed.

RESULTS AND CONCLUSIONS

The neurology group is small and hence is exposed to a large workload. The average number of patients seen daily by Indian neurologists is three to four times those seen by the United States and United Kingdom neurologists. Neurologists based at district places are more likely to see direct patients; whereas metropolitan neurologists see more referrals. Investigative facilities are available to neurologists but affordability is a concern. Clinical work leaves less time for academic and research activities, which the consultants are keen to participate in. In the privatized health system of India, emergency work constitutes a difficult area to cope with. The concept of single specialty group practice is welcomed by the majority with the idea of streamlining their work and life. These factors highlight an urgent need for increasing the neurology work force and argue for further involvement of primary physicians and internists in neurological care in India.

Melanosomal proteins promote melanin polymerization

In melanocytes, enzymes involved in the generation of melanin monomers are present and active in coated vesicles which are known to be acidic. Melanin polymerization however, occurs only in melanosomes. In vitro, it is not possible to generate melanin at the acidic pH of melanosomes using 3,4-dihydroxyphenylalanine (DOPA) and tyrosinase alone whereas melanin readily forms at higher pH with these reagents. Dimerization and elongation of the melanin polymer is known to require deprotonation. We have hypothesized that the amino acid side chains of melanosomal proteins act as proton acceptors to initiate polymerization and that the protonated basic groups serve to attract the negatively charged oligomers thus aiding polymerization and binding to proteins. We show that basic model proteins and basic premelanosomal proteins promote polymerization at an acidic pH and that positively charged surfaces allow binding of the growing melanin polymer. With progressive polymerization and exhaustion of the proton abstracting ability of melanosomal proteins, melanosomal pH drops further, which, we argue, is an additional controlling step that limits tyrosinase activity and melanin polymerization.

Donor corneal tissue evaluation

Proper evaluation of donor cornea is critical to the success of corneal transplantation. Attention must be paid to the cause of death and ocular condition as several general and ocular diseases constitute contraindications for donor corneal usage. Death to enucleation time should be noted. Gross examination and slit lamp biomicroscopy are mandatory for the evaluation of the donor eye while specular microscopy adds another useful dimension to information regarding donor cornea. This article provides a comprehensive review of all the aspects of donor corneal evaluation as practised today worldwide.