Dark continuous noise from mutant G90D-rhodopsin predominantly underlies congenital stationary night blindness.

Congenital stationary night blindness (CSNB) is an inherited retinal disease that causes a profound loss of rod sensitivity without severe retinal degeneration. One well-studied rhodopsin point mutant, G90D-Rho, is thought to cause CSNB because of its constitutive activity in darkness causing rod desensitization. However, the nature of this constitutive activity and its precise molecular source have not been resolved for almost 30 y. In this study, we made a knock-in (KI) mouse line with a very low expression of G90D-Rho (equal in amount to ~0.1% of normal rhodopsin, WT-Rho, in WT rods), with the remaining WT-Rho replaced by REY-Rho, a mutant with a very low efficiency of activating transducin due to a charge reversal of the highly conserved ERY motif to REY. We observed two kinds of constitutive noise: one being spontaneous isomerization (R*) of G90D-Rho at a molecular rate (R* s-1) 175-fold higher than WT-Rho and the other being G90D-Rho-generated dark continuous noise comprising low-amplitude unitary events occurring at a very high molecular rate equivalent in effect to ~40,000-fold of R* s-1 from WT-Rho. Neither noise type originated from G90D-Opsin because exogenous 11-cis-retinal had no effect. Extrapolating the above observations at low (0.1%) expression of G90D-Rho to normal disease exhibited by a KI mouse model with RhoG90D/WTand RhoG90D/G90D genotypes predicts the disease condition very well quantitatively. Overall, the continuous noise from G90D-Rho therefore predominates, constituting the major equivalent background light causing rod desensitization in CSNB.

Knowledge and attitudes about vitamin A consumption and its relationship with night blindness in university students.

Introduction: Night blindness is the first sign of vitamin A deficiency (VAD), which can lead to blindness if left untreated. University students may be at risk of VAD-related night blindness due to unhealthy eating attitudes and inadequate vitamin A intake. This study aimed to determine the relationship between knowledge and attitudes toward vitamin A consumption affecting night blindness in university students. Methods: This cross-sectional study involved 409 third-year university students of Universitas Islam Sultan Agung, Semarang, Indonesia. Participants completed questionnaires about socio-demographics, their knowledge of vitamin A, and attitudes toward vitamin A consumption. Night blindness symptoms among university students were assessed using the Low Luminance Questionnaire (LLQ), followed by a bivariate analysis of the Chi-Square test. Multivariate binary logistic regressions were used to determine whether the independent variables were associated with night blindness. A p-value less than 0.05 indicated significance. Results: The prevalence of high-symptom night blindness was higher among males (26.4%) than females (5.7%). Out of 409 university students, 48 from the non-medicine cluster of the study program had a night blindness symptom. The prevalence was lower in students who studied in the medicine cluster program. The level of knowledge on vitamin A had a significant relationship with symptoms of night blindness [prevalence ratio (PR) = 2.239 (95% CI = 1.110-4.516)]. The attitudes toward vitamin A consumption were significantly associated with night blindness (PR = 2.560, 95% CI = 1.215-5.392). Discussion: The results of this study show that the risk of night blindness in university students can be prevented by increasing their knowledge and attitudes toward consuming vitamin A-rich food. The university can provide health promotion and vitamin A supplementation to avoid night blindness among academia.

Clinical course of two siblings with potassium voltage-gated channel modifier subfamily V member 2 (KCNV2)-associated retinopathy.

BACKGROUND: KCNV2-associated retinopathy causes a phenotype reported as "cone dystrophy with nyctalopia and supernormal rod responses (CDSRR; OMIM# 610356)," featuring pathognomonic findings on electroretinography (ERG). Here, we report the clinical courses of two siblings with CDSRR. CASE REPORTS: Patient 1: A 3-year-old boy with intermittent exophoria was referred to our hospital. The patient's decimal best-corrected visual acuity (BCVA) at age 6 was 0.7 and 0.7 in the right and left eyes, respectively. Photophobia and night blindness were also observed. Because the ERG showed a delayed and supernormal b-wave with a "squaring (trough-flattened)" a-wave in the DA-30 ERG, and CDSRR was diagnosed. The patient's vision gradually worsened, and faint bilateral bull's eye maculopathy was observed at the age of 27 years, although the fundi were initially unremarkable. Genetic examination revealed a homozygous missense variant, c.529T > C (p.Cys177Arg), in the KCNV2 gene. Patient 2: The second patient was Patient 1's younger sister, who was brought to our hospital at 3 years of age. The patient presented with exotropia, mild nystagmus, photophobia, night blindness, and color vision abnormalities. The patients' decimal BCVA at age 13 was 0.6 and 0.4 in the right and left eyes, respectively, and BCVA gradually decreased until the age of 24 years. The fundi were unremarkable. The siblings had similar ERG findings and the same homozygous missense variant in the KCNV2 gene. CONCLUSIONS: The siblings had clinical findings typical of CDSRR. High-intense flash ERG is recommended for identifying pathognomonic "squaring" a-waves in patients with CDSRR.

Clinical vitamin A deficiency among preschool aged children in southwest Ethiopia.

Background: The clinical manifestations of vitamin A deficiency (VAD) involve night blindness, bitot's spots, corneal xerosis, and corneal scars. It is the most important cause of preventable childhood blindness among children and causes morbidity and mortality. Even though Ethiopia implemented high-potency vitamin A supplements, the occurrence of VAD remains significant. This study was to identify determinants of clinical VAD among preschool-aged children (PSC) in southwest Ethiopia. Method: A community-based survey was conducted among 411 randomly selected PSCs. A pretested and structured questionnaire coupled with clinical observation for signs of vitamin A deficiency by a trained ophthalmologist was used to collect the data. An anthropometric measurement of height was taken and analyzed using WHO Anthro to calculate Z-scores for each index. The public health significance of VAD was declared after comparison with international references. A bi-variable and multi-variable logistic analysis was done. We reported the adjusted odds ratio (AOR), 95% confidence interval, and p-value. Result: A total of 411 children were screened for clinical VAD, and the overall prevalence was 2.2% (95% CI: 1.5-2.5). Of which, night blindness affects 1.2%, bitot's spots affects 0.7%, and corneal xerosis affects 0.2%, indicating a major public health problem compared to the international reference. The odds of clinical VAD were 81% lower among children who received vitamin A supplementation (VAS; AOR = 0.19, 95% CI: 0.04-0.92). On the other hand, PSC of mothers who had attended ANC visits were 89% less likely to develop clinical VAD (AOR = 0.11, 95% CI: 0.02-0.53). In addition, the study revealed that the odds of developing clinical VAD are 82% lower among PSC aged 36 to 47 months (AOR = 0.18; 95% CI: 0.03-0.97). Conclusion: The prevalence of clinical VAD among PSC is a public health problem and is associated with ANC visits, VAS status, and the age of the child, which could be used to target interventions to further reduce existing VAD. Further studies using reliable dietary intake and biomarker data could further depict the burden of subclinical VAD.

Clinical and genetic studies for a cohort of patients with congenital stationary night blindness.

BACKGROUND: Congenital stationary night blindness (CSNB) is an inherited retinal disorder. Most of patients have myopia. This study aims to describe the clinical and genetic characteristics of fifty-nine patients with CSNB and investigate myopic progression under genetic cause. RESULTS: Sixty-five variants were detected in the 59 CSNB patients, including 32 novel and 33 reported variants. The most frequently involved genes were NYX, CACNA1F, and TRPM1. Myopia (96.61%, 57/59) was the most common clinical finding, followed by nystagmus (62.71%, 37/59), strabismus (52.54%, 31/59), and nyctalopia (49.15%, 29/59). An average SE of -7.73 ± 3.37 D progressed to -9.14 ± 2.09 D in NYX patients with myopia, from - 2.24 ± 1.53 D to -4.42 ± 1.43 D in those with CACNA1F, and from - 5.21 ± 2.89 D to -9.24 ± 3.16 D in those with TRPM1 during the 3-year follow-up; the TRPM1 group showed the most rapid progression. CONCLUSIONS: High myopia and strabismus are distinct clinical features of CSNB that are helpful for diagnosis. The novel variants identified in this study will further expand the knowledge of variants in CSNB and help explore the molecular mechanisms of CSNB.

Compound heterozygous mutations in GRM6 causing complete Schubert-Bornschein type congenital stationary night blindness.

Background: To explore the genetic defects of a Chinese family with complete Schubert-Bornschein type congenital stationary night blindness (CSNB). Methods: A Chinese family with complete Schubert-Bornschein type CSNB was enrolled in this study. The detailed ocular presentations of the patient were recorded. Targeted gene sequencing including 156 genes related to retinal diseases was used to detect the gene mutation. Sanger sequencing was performed to validate the potential pathogenic variants, and segregation analysis was performed on all available family members. Bioinformatics analysis was performed to predict the impact of the mutations. Results: By targeted gene sequencing and Sanger sequencing, we identified compound heterozygous mutations in GRM6: c.152G>T (p.Gly51Val) and c.727delG (p.Val243SerfsX21). Segregation analysis demonstrated that the mother of the proband carried the missense mutation (c.152G>T) while her father carried the frameshift mutation (c.727delG), indicating CSNB was autosomal recessively inherited in this family. Several bioinformatics prediction programs revealed the mutations were "Damaging" or "Disease Causing" and conservation analysis showed both the codons Gly51 and Val243 were highly conserved among species, suggesting the changes were pathogenic. Conclusion: By targeted gene sequencing and Sanger sequencing, we detected compound heterozygous mutations (c.152G>T, p.Gly51Val and c.727delG, p.Val243SerfsX21) in GRM6. The mutations co-segregated with the phenotype of the family members and are considered to be responsible for complete Schubert-Bornschein type CSNB. However, functional experiments in the future are needed to confirm the pathogenicity of the variants and to elucidate their exact molecular mechanisms causing CSNB.

Bilateral helicoid peri-papillary sub-retinal fibrosis due to a biallelic NR2E3 mutation: Describing variable expressivity of a mutation.

BACKGROUND: To describe different clinical presentations of a same NR2E3 recessive mutation in two families and within one family. DESIGN: Interventional family study. RESULTS: Our first case was a one-year-old male child with high hyperopia and refractive accommodative esotropia. In retinal examination, peri-papillary sub-retinal fibrosis with a helicoid configuration was observed in both eyes. The parents and the only sibling had no pathologic findings in the eyes. The child showed to have severely reduced responses in both photopic and scotopic electroretinogram components. In the genetic investigation, a homozygous autosomal recessive mutation in the NR2E3 gene (IVS1-2A > C) was discovered in the affected child, while the other family members were heterozygous for this mutation. We followed up with the patient for 3 years and no new lesion developed during this period. The second case was a 13-year-old male child referred to the retina clinic for decreased vision in the right eye. In retina examination, there were nummular pigmentary changes at the level of retinal pigment epithelium and along the vascular arcades with foveo-schitic changes in both eyes. A choroidal neovascularization (CNV) was noticed in the macula of his right eye. The genetic evaluation proved the same mutation in the NR2E3 gene as in the first case. Family history was remarkable for an uncle, an aunt, and two cousins with night blindness. CONCLUSION: Same NR2E3 gene mutation can cause heterogeneous clinical manifestations such as slight retinal changes in the absence of any visual symptoms to high hyperopia associated with helicoid peri-papillary sub-retinal fibrosis.

Congenital Stationary Night Blindness Structure, Function and Genotype-Phenotype Correlations in a Cohort of 122 Patients.

OBJECTIVE: To examine the molecular causes of Schubert-Bornschein (S-B) congenital stationary night blindness (CSNB), clinically characterize in detail, and assess genotype-phenotype correlations for retinal function and structure. DESIGN: Retrospective, longitudinal, single-center case series. PARTICIPANTS: One hundred twenty-two patients with S-B CSNB attending Moorfields Eye Hospital, United Kingdom. METHODS: All case notes, results of molecular genetic testing, and OCT were reviewed. MAIN OUTCOME MEASURES: Molecular genetics, presenting complaints, rates of nystagmus, nyctalopia, photophobia, strabismus, color vision defects and spherical equivalent refraction (SER). Retinal thickness, outer nuclear layer (ONL) thickness, and ganglion cell layer + inner plexiform layer (GCL+IPL) thickness from OCT imaging. RESULTS: X-linked (CACNA1F and NYX) and autosomal recessive (TRPM1, GRM6, GPR179 and CABP4) genotypes were identified. The mean (± standard deviation) reported age of onset was 4.94 ± 8.99 years. Over the follow-up period, 95.9% of patients reported reduced visual acuity (VA), half had nystagmus, and 64.7% reported nyctalopia. Incomplete CSNB (iCSNB) patients more frequently had nystagmus and photophobia. Nyctalopia was similar for iCSNB and complete CSNB (cCSNB). Color vision data were limited but more defects were found in iCSNB. None of these clinical differences met statistical significance. There was no significant difference between groups in VA, with a mean of 0.46 logarithm of the minimum angle of resolution, and VA remained stable over the course of follow-up. Complete congenital stationary night blindness patients, specifically those with NYX and TRPM1 variants, were more myopic. CACNA1F patients showed the largest refractive variability, and the CABP4 patient was hyperopic. No significant differences were found in OCT structural analysis during the follow-up period. CONCLUSIONS: Retinal structure in CSNB is stationary and no specific genotype-structure correlates were identified. Visual acuity seems to be relatively stable, with rare instances of progression. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Unusual OCT findings in a patient with CABP4-associated cone-rod synaptic disorder.

PURPOSE: Bi-allelic variants in CABP4 are associated with congenital cone-rod synaptic disorder, which has also been classified, electrophysiologically, as incomplete congenital stationary night blindness (iCSNB). We describe clinical findings in a patient who demonstrated an unusual macular optical coherence tomography (OCT) phenotype, not previously reported in this condition. METHODS: Our patient underwent multimodal retinal imaging, international standard full-field ERG testing and whole genome sequencing. RESULTS: The patient was a 60-year-old woman with non-progressive visual impairment since birth, nystagmus and preference for dim lighting. Clinical fundus examination was unremarkable. OCT imaging revealed a hypo-reflective zone under an elevated fovea in both eyes. ERGs showed an electronegative DA10 response, with severely abnormal light-adapted responses. Whole genome sequencing revealed homozygosity for a known pathogenic variant in CABP4. No variants were found in other genes that could explain the patient's phenotype. CONCLUSIONS: OCT findings of foveal elevation and an underlying hypo-reflective zone are novel in this condition. Whilst the clinical history was similar to achromatopsia and other cone dysfunction syndromes, ERG findings suggested disease associated with CACNA1F or CABP4. As CACNA1F is X-linked, CABP4 was more likely, and confirmed on genetic testing. The patient saw better in dim light, confirming that night blindness is not a feature of CABP4-associated disease. Our case highlights the value of ERGs in discriminating between causes of cone dysfunction, and extends the range of retinal imaging phenotypes reported in this disorder.

Etiology, Epidemiology, Pathophysiology, Signs and Symptoms, Evaluation, and Treatment of Vitamin A (Retinol) Deficiency.

Vitamin A, also known as retinol, is a non-water-soluble vitamin. Vitamin A is very important for the proper functioning of the human body. Retinol, especially in the form of retinyl ester, can be found in many animal-based products and is essential for the efficient operation of many physiological processes. Fruits and vegetables are also excellent sources of vitamin A; the majority of them include carotenoids, which are precursors to vitamin A. The human body has the ability to convert natural retinols like retinyl ester, retinoic acid, and provitamin A into biologically active forms that interact with a variety of molecular targets like nuclear receptors and retinal opsins. This review article provides knowledge regarding retinol deficiency in humans. It provides brief information about the sources, etiology, epidemiology, pathophysiology, and treatment of vitamin A deficiency.

Fundus Albipunctatus Associated with Biallelic LRAT Gene Mutation: A Case Report with Long-Term Follow-Up.

This case report presents a 26-year-old female patient diagnosed with fundus albipunctatus (FAP), a rare form of congenital stationary night blindness. The patient's clinical history and retinal findings spanning 23 years are consistent with FAP. The patient has profound night blindness, photophobia, and mild color vision changes with preserved best-corrected visual acuity (BCVA). Small white dots are present throughout the fundus, sparing the central macula. Electroretinograms (ERG) are consistent with congenital stationary night blindness (CSNB) and suggest a lack of rod response. Ophthalmic imaging has remained stable over time. Genetic testing revealed two biallelic missense mutations in the LRAT gene, c.197G>A (p.Gly66Glu) and c.557A>C (p.Lys186Thr). LRAT mutations are known to contribute to other retinal conditions but have not been previously associated with FAP. While there are currently no available treatments for FAP, this report expands our understanding of the genetic landscape of FAP to include LRAT and provides clinical data to support this finding.

The Value of Electroretinography in Identifying Candidate Genes for Inherited Retinal Dystrophies: A Diagnostic Guide.

Inherited retinal dystrophies (IRDs) are a group of heterogeneous diseases caused by genetic mutations that specifically affect the function of the rod, cone, or bipolar cells in the retina. Electroretinography (ERG) is a diagnostic tool that measures the electrical activity of the retina in response to light stimuli, and it can help to determine the function of these cells. A normal ERG response consists of two waves, the a-wave and the b-wave, which reflect the activity of the photoreceptor cells and the bipolar and Muller cells, respectively. Despite the growing availability of next-generation sequencing (NGS) technology, identifying the precise genetic mutation causing an IRD can be challenging and costly. However, certain types of IRDs present with unique ERG features that can help guide genetic testing. By combining these ERG findings with other clinical information, such as on family history and retinal imaging, physicians can effectively narrow down the list of candidate genes to be sequenced, thereby reducing the cost of genetic testing. This review article focuses on certain types of IRDs with unique ERG features. We will discuss the pathophysiology and clinical presentation of, and ERG findings on, these disorders, emphasizing the unique role ERG plays in their diagnosis and genetic testing.

Gene Therapy in Hereditary Retinal Dystrophies: The Usefulness of Diagnostic Tools in Candidate Patient Selections.

PURPOSE: Gene therapy actually seems to have promising results in the treatment of Leber Congenital Amaurosis and some different inherited retinal diseases (IRDs); the primary goal of this strategy is to change gene defects with a wild-type gene without defects in a DNA sequence to achieve partial recovery of the photoreceptor function and, consequently, partially restore lost retinal functions. This approach led to the introduction of a new drug (voretigene neparvovec-rzyl) for replacement of the RPE65 gene in patients affected by Leber Congenital Amaurosis (LCA); however, the treatment results are inconstant and with variable long-lasting effects due to a lack of correctly evaluating the anatomical and functional conditions of residual photoreceptors. These variabilities may also be related to host immunoreactive reactions towards the Adenovirus-associated vector. A broad spectrum of retinal dystrophies frequently generates doubt as to whether the disease or the patient is a good candidate for a successful gene treatment, because, very often, different diseases share similar genetic characteristics, causing an inconstant genotype/phenotype correlation between clinical characteristics also within the same family. For example, mutations on the RPE65 gene cause Leber Congenital Amaurosis (LCA) but also some forms of Retinitis Pigmentosa (RP), Bardet Biedl Syndrome (BBS), Congenital Stationary Night Blindness (CSNB) and Usher syndrome (USH), with a very wide spectrum of clinical manifestations. These confusing elements are due to the different pathways in which the product protein (retinoid isomer-hydrolase) is involved and, consequently, the overlapping metabolism in retinal function. Considering this point and the cost of the drug (over USD one hundred thousand), it would be mandatory to follow guidelines or algorithms to assess the best-fitting disease and candidate patients to maximize the output. Unfortunately, at the moment, there are no suggestions regarding who to treat with gene therapy. Moreover, gene therapy might be helpful in other forms of inherited retinal dystrophies, with more frequent incidence of the disease and better functional conditions (actually, gene therapy is proposed only for patients with poor vision, considering possible side effects due to the treatment procedures), in which this approach leads to better function and, hopefully, visual restoration. But, in this view, who might be a disease candidate or patient to undergo gene therapy, in relationship to the onset of clinical trials for several different forms of IRD? Further, what is the gold standard for tests able to correctly select the patient? Our work aims to evaluate clinical considerations on instrumental morphofunctional tests to assess candidate subjects for treatment and correlate them with clinical and genetic defect analysis that, often, is not correspondent. We try to define which parameters are an essential and indispensable part of the clinical rationale to select patients with IRDs for gene therapy. This review will describe a series of models used to characterize retinal morphology and function from tests, such as optical coherence tomography (OCT) and electrophysiological evaluation (ERG), and its evaluation as a primary outcome in clinical trials. A secondary aim is to propose an ancillary clinical classification of IRDs and their accessibility based on gene therapy's current state of the art. MATERIAL AND METHODS: OCT, ERG, and visual field examinations were performed in different forms of IRDs, classified based on clinical and retinal conditions; compared to the gene defect classification, we utilized a diagnostic algorithm for the clinical classification based on morphofunctional information of the retina of patients, which could significantly improve diagnostic accuracy and, consequently, help the ophthalmologist to make a correct diagnosis to achieve optimal clinical results. These considerations are very helpful in selecting IRD patients who might respond to gene therapy with possible therapeutic success and filter out those in which treatment has a lower chance or no chance of positive results due to bad retinal conditions, avoiding time-consuming patient management with unsatisfactory results.

Extended functional rescue following AAV gene therapy in a canine model of LRIT3-congenital stationary night blindness.

Congenital stationary night blindness (CSNB) is a group of inherited retinal diseases in which either rod-to-ON-bipolar cell (ON-BC) signaling, or rod function is affected leading to impaired vision under low light conditions. One type of CSNB is associated with defects in genes (NYX, GRM6, TRPM1, GPR179, and LRIT3) involved in the mGluR6 signaling cascade at the ON-BC dendritic tips. We have previously characterized a canine model of LRIT3-CSNB and demonstrated short-term safety and efficacy of an ON-BC targeting AAV-LRIT3 (AAVK9#4-shGRM6-cLRIT3-WPRE) gene therapy. Herein, we demonstrate long-term functional recovery and molecular restoration following subretinal injection of the ON-BC targeting AAV-LRIT3 vector in all eight treated eyes for up to 32 months. Following subretinal administration of the therapeutic vector, expression of the LRIT3 transgene, as well as restoration of mGluR6 signaling cascade member TRPM1, were confirmed in the outer plexiform layer (OPL) of the treated area. However, further investigation of the transgene LRIT3 transcript expression by RNA in situ hybridization (RNA-ISH) revealed off-target expression in non-BCs including the photoreceptors, inner nuclear, and ganglion cell layers, despite the use of a mutant AAVK9#4 capsid and an improved mGluR6 promoter designed to specifically transduce and promote expression in ON-BCs. While the long-term therapeutic potential of AAVK9#4-shGRM6-cLRIT3-WPRE is promising, we highlight the necessity for further optimization of AAV-LRIT3 therapy in the canine CSNB model prior to its clinical application.

Vitamin A Deficiency, COVID-19, and Rhino-Orbital Mucormycosis (Black Fungus): An Analytical Perspective.

Mucormycosis is a rare but serious opportunistic fungal disease characterized by rhino-orbito-cerebral and pulmonary involvement. It is mainly seen in people with secondary immunosuppression, isolated vitamin A deficiency, measles, and AIDS patients. It showed a rise during the second wave of the COVID-19 epidemic in the spring of 2021 in India, especially in diabetic COVID-19 patients. Vitamin A deficiency is known to cause nutritional immunodeficiency and hence leading the way to increased opportunistic fungal, bacterial, and viral infections. In the eye, it causes keratitis, night blindness, xerophthalmia, conjunctivitis, Bitot spots, keratomalacia, and retinopathy. It also causes decreased tear secretion and deterioration of the anatomical/physiological defense barrier of the eye. The negative impact of vitamin A deficiency has been previously demonstrated in measles, AIDS, and COVID-19. We think that mucormycosis in COVID-19 might be rendered by vitamin A deficiency and that vitamin A supplementation may have preventive and therapeutic values against mucormycosis and other ocular symptoms associated with COVID-19. However, any vitamin A treatment regimen needs to be based on laboratory and clinical data and supervised by medical professionals.

Vitamin-A enriched yogurt through fortification of pumpkin (Cucurbita maxima): A potential alternative for preventing blindness in children.

Vitamin-A deficiency associated with night blindness in children is a global health problem that could be prevented or reduced by promoting the intake of ß-carotene in food. The fortification of ß-carotene in yogurt using pumpkin flesh (PF) could be a very cost-effective public health intervention. The current study aimed to analyze the proximate, functional, microbial, textural, and sensory properties of yogurt fortified with PF to evaluate its suitability as a ß-carotene enriched food. The research was conducted with three treatments, control set-type yogurt (CSY) with no PF, 15% PF-fortified set-type yogurt (15PFSY), and 20% PF-fortified set-type yogurts (20PFSY) followed by pumpkin pie spice and ground pumpkin seed to improve consumer acceptability. The fortified yogurt with 20PFSY and 15PFSY contained a higher amount of ß-carotene, protein, fiber, and ash, and lower carbohydrate, fat, and energy in compression with CSY, which might attract health-conscious people. In addition, viable bacterial count, firmness, consistency, cohesiveness, and viscosity index were found better in fortified yogurt. Based on reports of sensory panellists, 15PFSY achieved a significantly (p < 0.01) highest overall acceptability than 20PFSY and CSY. These findings suggest that pumpkin-fortified yogurt could be used widely as a nutrient-enriched fermented food. In addition, as a ß-carotene (vitamin-A) fortified yogurt, it could be a potential alternative to prevent or reduce blindness in children with minimal cost.

Ocular complications in live-related renal transplant recipients: A single-centre study.

Renal transplantation is considered to be the treatment of choice for patients with end-stage kidney failure. While transplantation has a high success rate, there are a number of associated challenges which include those related to the primary disease, transplant procedure as well as medications that are necessary to take after transplantation. Steroids, for instance, have been reported to lead to ocular complications in patients who have undergone renal transplantation in other parts of the world. This retrospective case series reports the pattern of ocular complications among patients who underwent renal transplant since the inception of ophthalmology clinic at a dialysis and transplant centre in Karachi, Pakistan. The case series corroborates the findings of other similar studies from around the world, with cataract being the most common occurrence in this cohort. A unique finding in Pakistani setup includes the high prevalence of night blindness, which requires investigation in a larger cohort prospectively.

Whale shark rhodopsin adapted to deep-sea lifestyle by a substitution associated with human disease.

Spectral tuning of visual pigments often facilitates adaptation to new environments, and it is intriguing to study the visual ecology of pelagic sharks with secondarily expanded habitats. The whale shark, which dives into the deep sea of nearly 2,000 meters besides near-surface filter feeding, was previously shown to possess the 'blue-shifted' rhodopsin (RHO), which is a signature of deep-sea adaptation. In this study, our spectroscopy of recombinant whale shark RHO mutants revealed that this blue shift is caused dominantly by an unprecedented spectral tuning site 94. In humans, the mutation at the site causes congenital stationary night blindness (CSNB) by reducing the thermal stability of RHO. Similarly, the RHO of deep-diving whale shark has reduced thermal stability, which was experimentally shown to be achieved by site 178 and 94. RHOs having the natural substitution at site 94 are also found in some Antarctic fishes, suggesting that the blue shift by the substitution at the CSNB site associated with the reduction in thermal stability might be allowed in cold-water deep-sea habitats.

Characterization of two pathological gating-charge substitutions in Cav1.4 L-type calcium channels.

Cav1.4 L-type calcium channels are predominantly expressed at the photoreceptor terminals and in bipolar cells, mediating neurotransmitter release. Mutations in its gene, CACNA1F, can cause congenital stationary night-blindness type 2 (CSNB2). Due to phenotypic variability in CSNB2, characterization of pathological variants is necessary to better determine pathological mechanism at the site of action. A set of known mutations affects conserved gating charges in the S4 voltage sensor, two of which have been found in male CSNB2 patients. Here, we describe two disease-causing Cav1.4 mutations with gating charge neutralization, exchanging an arginine 964 with glycine (RG) or arginine 1288 with leucine (RL). In both, charge neutralization was associated with a reduction channel expression also reflected in smaller ON gating currents. In RL channels, the strong decrease in whole-cell current densities might additionally be explained by a reduction of single-channel currents. We further identified alterations in their biophysical properties, such as a hyperpolarizing shift of the activation threshold and an increase in slope factor of activation and inactivation. Molecular dynamic simulations in RL substituted channels indicated water wires in both, resting and active, channel states, suggesting the development of omega (ω)currents as a new pathological mechanism in CSNB2. This sum of the respective channel property alterations might add to the differential symptoms in patients beside other factors, such as genomic and environmental deviations.