A perylenemonoimide-based fluorescent probe: ultrasensitive and selective tracing of endogenous peroxynitrite in living cells.

Peroxynitrite (ONOO-), a highly reactive species, plays a key role in various physiological and pathological processes. Herein, a red-emitting fluorescent reporter perylenemonoimide-boronate ester (PMI-BE) was synthesized and utilized for ultrasensitive detection of ONOO-. The unique feature of PMI-BE is its nanomolar sensitivity with high selectivity towards ONOO-. Moreover, PMI-BE also detects endogenously generated ONOO- in live cells.

Structural and mechanistic insights into modulation of α-Synuclein fibril formation by aloin and emodin.

α-Synuclein (α-Syn) aggregation/fibrillation is a leading cause of neuronal death and is one of the major pathogenic factors involved in the progression of Parkinson's' disease (PD). Against this backdrop, discovering new molecules as inhibitors or modulators of α-Syn aggregation/fibrillation is a subject of enormous research. In this study, we have shown modulation, disaggregation, and neuroprotective potential of aloin and emodin against α-Syn aggregation/fibrillation. Thioflavin T (ThT) fluorescence assay showed an increase in lag phase from (51.14 ± 2) h to (68.58 ± 2) h and (74.14 ± 3) h in the presence of aloin and emodin respectively. ANS binding assay represents a modulatory effect of these molecules on hydrophobicity which is crucial for aggregates/fibril formation. NMR spectroscopy and tyrosine quenching studies reveal the binding of aloin/emodin with monomeric α-Syn. TEM and DLS micrographs illustrate the attenuating effect of aloin/emodin against the development of large aggregates/fibrils. Our seeding experiments suggest aloin/emodin generate seeding incompetent oligomers that direct the off-pathway aggregation/fibrillation. Also, aloin/emodin capably reduces the fibrils-induced cytotoxicity and disassembles the preexisting amyloid fibrils. These findings provide deep insight into the modulatory mechanism of α-Syn aggregation/fibrillation in the presence of aloin and emodin, thereby suggesting their potential roles as promising therapeutic molecules against aggregation/fibrillation related disorders.

Ellagic Acid Modulates Uninduced as well as Mutation and Metal-Induced Aggregation of α-Synuclein: Implications for Parkinson's Disease.

α-Synuclein (αS) is an intrinsically disordered protein whose aggregation and deposition in Lewy bodies is involved in the progression of Parkinson's disease (PD) and other related disorders. The aggregation process of αS is also triggered by mutations like A53T and E46K in the SNCA gene and disruption in metal-ion homeostasis. Currently, there is no obviating therapy available in the market that could effectively prevent the progression of the disease. In this backdrop, there exists an emerging need to consider naturally occurring polyphenols and flavonoids as potential therapeutic agents against PD. In this study, we demonstrate the modulatory effect of ellagic acid (EA) against wild-type as well as mutation and metal-induced aggregation of αS. Thioflavin T (ThT) fluorescence assay suggests that EA acts on the nucleation phase of αS fibrillization, thereby increasing the lag phase from 21.33 ± 3.01 to 48.20 ± 5.05 h and reducing the fibrils growth rate from 4.60 ± 2.06 to 0.890 ± 0.36 h-1. 8-Anilino-1-naphthalene sulfonic acid (ANS), Congo red (CR), and intrinsic fluorescence studies indicate that the interaction of EA with αS facilitates the structural changes in the protein that lead to inhibition of fibril formation. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) images illustrate that the size of fibrils diminishes up to 100 nm in the presence of EA. Dot blot and seeding experiments put forward that EA directs the αS aggregation toward off-pathway fibrillization. Our 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay deciphers the role of EA in minimizing the αS fibril-induced toxicity, thereupon leading to an increase in cell viability. Also, EA attenuates both mutations as well as metal-induced αS fibrillization and disaggregates the preexisting fibrils. Additionally, computational studies elucidate that EA preferentially interacts with the N-terminal and NAC domain of αS. Hence, this work reveals the aggregation inhibition mechanism of EA and provides considerable therapeutic interventions against PD and related disorders.

Island cartilage vs temporalis fascia in type 1 tympanoplasty: A prospective study / Cartílago en isla vs. fascia de músculo temporal en timpanoplastia tipo 1: un estudio prospectivo

OBJECTIVE: (1) To compare the results of graft take-up and audiological outcome of temporalis fascia versus island cartilage graft in type 1 tympanoplasty. (2) To compare the rate of postoperative retraction of neotympanum in both. METHODS: A prospective study was conducted on 70 patients of ages ranging from 11 to 50 years with dry subtotal perforation. 35 underwent island cartilage tympanoplasty and 35 underwent type 1 tympanoplasty using temporalis fascia graft. Graft acceptance rates and post-operative audiograms were compared. RESULTS: At one year follow up, the graft take-up rate for temporalis fascia and island cartilage graft were found to be 82.9% and 97.1% respectively, which was found to be statistically significant (p < 0.05). In the temporalis fascia group, two out of 35 patients (5.7%) had retraction of the neo tympanum. There was no incidence of retraction using island cartilage graft. There was no significant difference in the postoperative air-bone gap gain between temporalis fascia graft and island cartilage graft. CONCLUSION: Island cartilage tympanoplasty shows a high degree of reliability in high risk cases. It has a higher graft take-up rate with no incidence of retraction of neotympanum. Moreover, it provided significant hearing improvement in our patients

OBJETIVO: 1) Comparar los resultados del injerto y el resultado audiológico de la fascia del músculo temporal versus injerto de cartílago en isla en la timpanoplastia tipo 1, y 2) Comparar la tasa de retracción postoperatoria del neotímpano en ambos. MÉTODOS: Se realizó un estudio prospectivo en 70 pacientes de edades comprendidas entre los 11 y 50 años con perforación subtotal en seco. En 35 de ellos se realizó timpanoplastia con cartílago en isla y a los 35 restantes timpanoplastia tipo 1 mediante injerto de fascia de músculo temporal. Se compararon las tasas de aceptación del injerto y los audiogramas postoperatorios. RESULTADOS: Al año de seguimiento, la tasa de toma del injerto de fascia de músculo temporal y el injerto de cartílago en isla fue del 82,9 y 97,1%, respectivamente, que resultó estadísticamente significativa (p < 0,05). En el grupo de fascia de músculo temporal, 2 de 35 pacientes (5,7%) tuvieron una retracción del neotímpano. No hubo incidencia de retracción en el injerto de cartílago en isla. No hubo diferencia significativa en cuanto a la ganancia en el umbral diferencial de audición entre los injertos de fascia de músculo temporal y cartílago en isla. CONCLUSIÓN: La timpanoplastia con cartílago en isla muestra un alto grado de fiabilidad en casos de alto riesgo. Tiene una mayor tasa de aceptación del injerto, sin incidencias de retracción del neotímpano. Además, aportó una importante mejora de audición a nuestros pacientes

Island cartilage vs temporalis fascia in type 1 tympanoplasty: A prospective study.

OBJECTIVE: (1) To compare the results of graft take-up and audiological outcome of temporalis fascia versus island cartilage graft in type 1 tympanoplasty. (2) To compare the rate of postoperative retraction of neotympanum in both. METHODS: A prospective study was conducted on 70 patients of ages ranging from 11 to 50 years with dry subtotal perforation. 35 underwent island cartilage tympanoplasty and 35 underwent type 1 tympanoplasty using temporalis fascia graft. Graft acceptance rates and post-operative audiograms were compared. RESULTS: At one year follow up, the graft take-up rate for temporalis fascia and island cartilage graft were found to be 82.9% and 97.1% respectively, which was found to be statistically significant (p<0.05). In the temporalis fascia group, two out of 35 patients (5.7%) had retraction of the neo tympanum. There was no incidence of retraction using island cartilage graft. There was no significant difference in the postoperative air-bone gap gain between temporalis fascia graft and island cartilage graft. CONCLUSION: Island cartilage tympanoplasty shows a high degree of reliability in high risk cases. It has a higher graft take-up rate with no incidence of retraction of neotympanum. Moreover, it provided significant hearing improvement in our patients.

Cardiac complications in diphtheria and predictors of outcomes.

OBJECTIVE: To study the cardiac complications in diphtheria patients and to study the predictors of outcomes. STUDY DESIGN: Single centre prospective analysis of cardiac complications in diphtheria patients. RESULTS: In this study, there were 60 patients diagnosed with diphtheria with ECG changes. The ECG changes seen were sinus tachycardia (68.3%), T wave inversion (20%), ST segment depression (13.3%), right bundle branch block (5%), multiple atrial ectopics (3.3%). The case fatality rate in our study was 25% (15 patients). High CPK-MB, myoglobulin and cardiac troponin levels were associated with cardiac mortality. In our study, cardiac troponin T had the highest sensitivity (80%) and CK-MB had the highest specificity (95.56%). CONCLUSION: Cardiac involvement is a common complication of infection with C. diphtheria and is associated with high mortality. As diphtheria can be prevented by adequate vaccination, efforts should be maximized for high vaccine coverage with booster doses.

Diphtheria: It is still prevalent!!!

BACKGROUND: Diphtheria is a respiratory infectious disease of childhood. It is a fatal disease and may cause complications if not recognized early and treated properly. Despite availability of effective vaccination it continues to be reported from many parts of the world particularly developing countries. OBJECTIVE: To assess the demographic and clinical characteristics of diphtheria patients, and the predictors of outcomes of respiratory diphtheria. METHODS: A prospective analysis of 180 patients with a clinical diagnosis of respiratory diphtheria admitted from 2011 to 2014 at a tertiary referral hospital. They were evaluated with respect to demographic details, immunization status, clinical features, complications and outcomes. RESULTS: Most common age group affected was children less than 5 years of age (87 cases, 48.33%). The peak incidence of diphtheria was seen in the months of September and October (111 cases, 62%). Majority of the patients were unimmunized (54%), followed by partially immunized (21%). The most common complication was respiratory in 80 cases (44%), followed by cardiac complications in 54 cases (30%), and renal (16%) and neurological complications (10%). Cardiac complications were associated with the highest mortality rate (63%). The presence of bull neck and pseudomembrane score >2 was associated with a high mortality. CONCLUSION: Diphtheria is still a preventable public health problem in many developing countries. Improved vaccination coverage, including booster dosage, coupled with early detection and effective treatment, may all reduce incidence and mortality.