Toward robust and privacy-enhanced facial recognition: A decentralized blockchain-based approach with GANs and deep learning.

In recent years, the extensive use of facial recognition technology has raised concerns about data privacy and security for various applications, such as improving security and streamlining attendance systems and smartphone access. In this study, a blockchain-based decentralized facial recognition system (DFRS) that has been designed to overcome the complexities of technology. The DFRS takes a trailblazing approach, focusing on finding a critical balance between the benefits of facial recognition and the protection of individuals' private rights in an era of increasing monitoring. First, the facial traits are segmented into separate clusters which are maintained by the specialized node that maintains the data privacy and security. After that, the data obfuscation is done by using generative adversarial networks. To ensure the security and authenticity of the data, the facial data is encoded and stored in the blockchain. The proposed system achieves significant results on the CelebA dataset, which shows the effectiveness of the proposed approach. The proposed model has demonstrated enhanced efficacy over existing methods, attaining 99.80% accuracy on the dataset. The study's results emphasize the system's efficacy, especially in biometrics and privacy-focused applications, demonstrating outstanding precision and efficiency during its implementation. This research provides a complete and novel solution for secure facial recognition and data security for privacy protection.

Transoral endoscopic thyroidectomy vestibular approach, adaptation of modern surgical technique in a developing country.

Conventional thyroidectomy has been the standard technique for over 100 years but has the drawback of leaving a scar on the neck. As such, the demand for minimally invasive endoscopic thyroid surgery is rapidly growing as patients are becoming more and more worried about scars; it is more appropriate in patients who want to get surgery done because of odd looking swelling over the neck. TOETVA is safe, feasible, effective, and scar-free alternative to conventional thyroid surgery. We are sharing our first clinical experience in TOETVA in Pakistan with effective outcome in terms of surgical complication and patient satisfaction.

Phylogenetic and antigenic analysis of infectious bronchitis virus isolated from commercial and backyard chickens in Pakistan, 2015-2018.

Infectious bronchitis virus (IBV) is a rapidly evolving virus affecting both vaccinated and unvaccinated poultry flocks and is responsible for significant economic losses globally; hence, it is imperative to obtain a deeper understanding of this pathogen. In this study, seven IBV strains were isolated from commercial and backyard poultry flocks during 2015-2018. We obtained full-length IBV genomes of two viruses using the Illumina sequencing method, while five additional viruses were genetically characterized through full-length spike (S1) gene sequencing. Phylogenetic and distance analysis based on complete S1 gene and full-length genome sequences revealed that one IBV isolate belonged to genotype GI-1 and six viruses were clustered within genotype GI-13. Deduced amino acid sequences of GI-13 strains exhibited 31.8-37.2 % divergence with the commonly used classic vaccine strains (M41) and 2.7-12.6 % with variant vaccine strains (4/91) in Pakistan. High evolutionary distances suggest that the IBV viruses circulating in Pakistan are under continuous evolutionary pressure. Moreover, ch/IBV/Pak/AW-2/2017 was found to have originated from an intra-genotypic recombination event between the variant group (GI-23 lineage as a major parent) and variant vaccine strain (4/91-like as a minor parent) and is the first example of recombination within genotype GI-13 in Pakistan. Together, these findings provide genetic and evolutionary insights into the currently circulating IBV genotypes in Pakistan, which could help to better understand the origin, spread and evolution of IBVs, and to ascertain the importance of disease monitoring as well as re-evaluation forof currently used vaccines and vaccination programmes.

Forecasting real exchange rate (REER) using artificial intelligence and time series models.

Forecasting is an attractive topic in every field of study because no one knows the exact nature of the underlying phenomena, but it can be guessed using mathematical functions. As the world progresses towards technology and betterment, algorithms are updated to understand the nature of ongoing phenomena. Machine learning (ML) algorithms are an updated phenomenon used in every task aspect. Real exchange rate data is assumed to be one of the significant components of the business market, which plays a pivotal role in learning market trends. In this work, machine learning models, i.e., the Multi-layer perceptron model (MLP), Extreme learning machine (ELM) model and classical time series models are used, Autoregressive integrated moving average (ARIMA) and Exponential Smoothing (ES) model to model and predict the real exchange rate data set (REER). The data under consideration is from January 2019 to June 2022 and comprises 864 observations. This study split the data set into training and testing and applied all stated models. This study selects a model that meets the Key Performance Indicators (KPI) criteria. This model was selected as the best candidate model to predict the behaviour of the real exchange rate data set.

Understanding the dynamics of capital structure, corporate governance, and corporate social responsibility in high- and low-leveraged US and Chinese firms.

Corporate social responsibility turned into a global sensation from the inception of the twenty-first century in the corporate world and grabbed immense engrossment from all stakeholders in their decision-making process. Capital structure and corporate governance practices are the well-mellowed facets of corporate finance literature. In this study, the moderating role of corporate social responsibility (CSR) between corporate governance and leverage of the US and Chinese listed firms has been established, with a further extension of analyzing the moderating role of CSR between corporate governance and leverage in high vs low leveraged firms and high CSR vs low CSR firms as the novelty of this study and has never been examined in both economies and globally. The data of 1989 Chinese-listed firms from 28 sectors of the economy and 6640 US-listed firms from 27 sectors of the economy has been taken from 2001 to 2019 and analyzed through fixed effect regression and system generalized method of moment (GMM). Results of the study reveal that CSR and corporate governance are negatively associated with the leverage of both Chinese and US firms. Moreover, the moderating role of CSR has established between corporate governance and leverage negative relationship. The moderating role of CSR in the relationship of leverage and corporate governance is established only in low-leveraged firms whereas it is insignificant in high-leveraged firms. System GMM confirms the signs and significance of the regression results; that is why regression results are robust and reliable, and there is no endogeneity problem in our model. The study also gives an insight for future research on high- and low-leveraged firms and firms with more CSR score than less CSR score with other dimensions such as firm performance and firm value variables.

Comparison of Endoscopic Versus Microscopic Tympanoplasty.

Introduction: Tympanoplasty is a common surgery for chronic otitis media and has conventionally been performed with a microscope for decades. The trend of endoscopic minimally invasive surgeries has been increasing worldwide for the last few decades. Few studies have discussed the outcomes of tympanoplasty with microscope and tympanoplasty with endoscope . This study aims to compare results of tympanoplasty done with microscope vs endoscope in terms of graft take rate and improvement in conductive hearing loss. Materials and Methods: We did a retrospective review of 120 patients (54 male and 66 female) who underwent Type I tympanoplasty at Liaquat National Postgraduate Medical Center from January 2019 to January 2020. We included 60 patients who underwent tympanoplasty with microscope and 60 patients who underwent tympanoplasty with endoscope. Postoperative graft uptake and hearing improvement were studied. Results: Overall mean preoperative hearing loss was 30.24 (±9.61) dB as compared to mean postoperative hearing loss, which was reduced to 19.36 ( ±8.54) dB, and the difference was significant (P-value <0.001. No statistically significant difference was found for air-bone gap closure between the two groups (P-value 0.78). Out of 120 patients, overall successful graft uptake was seen in 109 (90.8%). In tympanoplasty with microscope, graft take was 90.0%, compared to 91.6% in endoscope group. There was no significant difference in graft take in the two groups. Conclusions: The tympanoplasty with endoscope is comparable to tympanoplasty with microscope in terms of graft uptake and hearing improvement.

Role of Lactobacillus plantarum 299v versus Placebo in symptomatic improvement of irritable bowel syndrome patients.

Objectives: To find the efficacy of lactobacillus plantarum 299v compared to placebo in symptomatic improvement of irritable bowel syndrome patients. METHODS: The randomised control trial was conducted at the Lady Reading Hospital, Peshawar, Pakistan, from July 20, 2014, to January 20, 2015, and comprised irritable bowel syndrome patients who were randomised into intervention group A treated with lactobacillus plantarum 299v and control group B treated with placebo. Symptoms, like abdominal pain, bloating and complete rectal emptying, were noted and compared between the groups. Data was analysed using SPSS 19. RESULTS: Of the 190 patients assessed, 120(63%) were included; 60(50%) in each of the two groups. After loss to follow-up, the study was completed by 55(91.7%) in group A and 53(88.3%) in group B. The mean age in group A was 37.53±9.02 and it was 34.40±11.23 in group B (p=0.652). The male-to-female ratio and irritable bowel syndrome type in both the groups was not significantly different (p>0.055). There was no significant difference in terms of relieving abdominal pain, bloating and rectal emptying between the groups (p>0.05). CONCLUSIONS: No significant efficacy was established in favour of treating in irritable bowel syndrome with lactobacillus plantarum 299v. Trials Registration: IRCT20200504047303N1.

Frequency of De Novo Hepatocellular Carcinoma after Direct-acting Antiviral Therapy for Chronic Hepatitis C: A Prospective Follow-up.

Background: Chronic hepatitis C (CHC) management has changed tremendously after direct-acting antivirals (DAAs) availability. Sustained virological response (SVR) has improved significantly, but one of the major concerns is the chances of de novo hepatocellular carcinoma (HCC) development after DAAs. The objective of the study is to calculate the frequency of newly diagnosed cases of HCC after antiviral therapy for CHC in Pakistan. Materials and methods: This prospective, interventional research was conducted from June 2017 to September 2020. All patients after antiviral therapy for CHC were followed with an ultrasound abdomen and α-fetoprotein, six monthly. Multiphasic computed tomography (CT) of the abdomen was performed in suspected cases. For quantitative variables, the mean and standard deviations were calculated, whereas the qualitative variables were analyzed by frequencies and percentages. Results: Among 180 patients, 110 were men and 70 were women with a mean age of 45.52 ± 11.71 years. One hundred and twenty-six patients were noncirrhotic, 38 had compensated cirrhosis while 16 had decompensated cirrhosis. One hundred and sixty-four (91.11%) patients achieved SVR, of which 22 (12.22%) patients developed new HCC during follow-up. Compensated cirrhosis group had 10 patients, the decompensated group had 12 patients, and the noncirrhotic group had no new HCC cases. Among patients with the new HCC, 12 achieved SVR. Conclusion: The risk of the development of HCC after antiviral treatment is highly significant among patients with liver cirrhosis. So, a strict surveillance strategy should be adopted in every cirrhotic patient following treatment with DAA agents even if they achieve SVR. Clinical significance: Chances of developing HCC are still significantly high even after achieving SVR with DAAs in patients with liver cirrhosis.Patients with liver cirrhosis should be under surveillance for HCC even after achieving SVR after DAAs treatment. How to cite this article: Rasool S, Hanif S, Ahmad A, et al. Frequency of De Novo Hepatocellular Carcinoma after Direct-acting Antiviral Therapy for Chronic Hepatitis C: A Prospective Follow-up. Euroasian J Hepato-Gastroenterol 2022;12(2):73-76.

Occult Nodal Metastasis in Oral Cavity Cancers.

INTRODUCTION:  In squamous cell carcinoma (SCC) of the oral cavity, there is always a risk of occult metastasis to neck nodes in the clinically and radiologically negative neck (N0). Therefore, elective neck dissection (END) has ever been under discussion since the beginning of their routine use for the management of neck for oral carcinomas. The purpose of the current study is to identify the percentage of occult nodal metastasis to neck levels I-V in the cases of oral carcinoma who were treated for the N0 with END. METHODS:  Patients who were treated between June 2005 and May 2010 with END from neck levels I to V for the management of N0 with oral SCC had been identified from the database of Aga Khan University Hospital. Those who met the inclusion and exclusion criteria were included in the study. Data were analyzed using SPSS 16 software. Using descriptive statistics, the mean was computed for the quantitative variable (age). Frequencies and percentages were calculated for gender, site, tumor grade, and lymph node involvement for each neck level. RESULTS:  A total of 50 patients were included in the study. There were 38 males and 12 females. The mean age was 47 (range 25-72). The most common site of the tumor was buccal mucosa in 50% of the cases followed by tongue 20%, then floor of mouth 14%, dentoalveolar ridge 8%, retromolar area 4%, lip 2%, and hard palate 2%. Histopathological grading of tumors showed well-differentiated 28%, moderately differentiated 33%, and poorly differentiated 6%. Twenty-seven out of 50 patients were found positive for nodal metastasis on final postoperative histopathology. Neck node metastasis at level I was found in 22 patients, at level II in 16 patients, at level III in seven patients, and at level IV in two patients. The level V was found free of metastasis in all of the cases. CONCLUSION:  The rate of occult metastatic disease to the neck nodes was similar to that found in the literature. Both early and advanced local disease is associated with a risk of occult metastasis. END for neck levels I-V is, therefore, recommended for the management of the N0 in all cases of oral SCCs. Spread to levels IV and V is rare and these levels should not be a part of routine END.

Screening Programs for Hearing Assessment in Newborns and Children.

Objective In this study, we aimed to assess the incidence of hearing loss in the pediatric population through otoacoustic emission (OAE) and brainstem evoked response audiometry (BERA) and to analyze the possible etiological factors responsible for it. Material and methods A retrospective observational study was conducted in the Otolaryngology (ENT) and Gynecology and Obstetrics Departments at the Jinnah Postgraduate Medical Centre and National Institute of Child Health in Karachi, Pakistan between July 2019 and October 2019. The convenient sampling technique was used to select the patients. The final sample size consisting of newborns and children was 108. Initially, screening procedures were undertaken for newborns to detect permanent or fluctuating, bilateral or unilateral, and sensory or conductive hearing loss, averaging 30-40 dB or more in the frequency region, which indicated potential issues related to speech recognition (approximately 500-4,000 Hz). The screening of newborns involved the use of non-invasive, objective physiologic measures that included OAEs and/or auditory brainstem response (ABR). The children with hearing impairment then underwent BERA; thereafter, further investigations were performed to confirm the defects found on BERA testing. Results Of the 108 cases, 96 had normal hearing on OAE screening, and 12 were found to have hearing loss on the OAE test. Further testing was carried out on BERA for 12 cases that had been detected to have hearing loss on OAE, and BERA showed normal hearing for five cases whereas seven were found to have hearing loss. Of the seven patients with hearing loss on the BERA test, five were diagnosed with cochlear deafness, and two had retrocochlear deafness. Conclusion Our present study concludes that in order to avoid any hearing problems in infants, OAE hearing screening and diagnostic BERA screening programs should be carried out in all the hospitals of Pakistan to assess newborn hearing at an early age.

Myoepithelial Carcinoma of the Floor of the Mouth: A Rare Salivary Gland Tumor in an Unusual Location.

Myoepithelial carcinomas are rare malignant salivary gland tumours encountered most commonly in the parotid gland and are amenable to surgical resection. However, when they occur at complex anatomical locations, complete resection becomes difficult due to their locally aggressive nature. Here we describe a case of a large myoepithelial carcinoma arising in the floor of the mouth and involving major structures at the skull base. A 30-year-old female presented with a slow-growing mass in the oral cavity. Computed tomography (CT) scan showed a heterogeneous appearing lesion in the mouth floor measuring 6.7 x 5.8 x 7.3 cm. Superiorly, the lesion was extending up to the skull base, laterally extending up to the parotid gland and inferiorly up to the submandibular gland. This lesion was also encasing the internal carotid artery. Incisional biopsy under local anaesthesia was performed, and the specimen was sent for histopathological analysis. Microscopic examination showed a neoplastic lesion composed of sheets of cells with oval nuclei and clear cytoplasm with a myxoid background. Immunohistochemical expression of pan-cytokeratin (CKAE1/AE3), p63, anti-smooth muscle actin (ASMA) and glial fibrillary acidic protein (GFAP) supported the diagnosis of myoepithelial neoplasm. The patient then underwent excision of the mass followed by histological analysis, which further showed microscopic evidence of infiltration into the surrounding tissue along with areas of atypia and significant mitoses. These morphological findings supported the diagnosis of myoepithelial carcinoma. The excised tumour was reaching up to the excision margin. Myoepithelial carcinomas are rare malignant tumours with diverse histomorphological patterns frequently present as a diagnostic challenge. The mainstay of treatment is complete surgical excision with disease-free margins, which can be challenging due to local aggressiveness and large size of these tumours. When these tumours occur in complex anatomical locations, complete excision becomes difficult, resulting in a dismal prognosis.

Industrialization, Freight Transport and Environmental Quality: Evidence from Belt and Road Initiative Economies.

Belt and Road initiative has been proposed by China to initiate the cooperation among relevant countries in sector of energy and Trade. The study investigate highlighting the relationship between industrial value added per capita, transport freight and CO2 emission among the partner countries of Belt and Road initiatives by using panel of 33 economies from 1986-2017. Study includes panel autoregressive distributed lag model (ARDL) to estimate the long-run relationship among variables. Estimated results of pool mean group (PMG) indicates that increase in industrial value added per capita and transport freight deteriorates the quality of environment in long-run. However, short-run results of granger causality reveals positive and unidirectional causality running from industrial value added per capita to emission of CO2 while transport freight and CO2 emission shows bidirectional causality. The study emphasized to formulate environment friendly policies in industrial and transport sector.

Agriculture development and CO2 emissions nexus in Saudi Arabia.

The agriculture sector may help to improve the environment of any country. The purpose of this research is to test the existence of environmental Kuznets curve (EKC) hypothesis while keeping the energy consumption and agriculture share in income into account and analyze their effects on the CO2 emissions per capita of Saudi Arabia. We test both symmetrical, asymmetrical and quadratic effects of agriculture sector on the CO2 emissions. An inverted U-shaped relationship between gross domestic product (GDP) per capita and CO2 emissions per capita is found. Hence, EKC hypothesis is validated with a turning point at GDP per capita of 77,068 constant Saudi Riyal. Further, a negative and significant effect of agriculture sector on the CO2 emissions per capita has been found both in symmetrical and asymmetrical analyses. The magnitudes of effects of increasing and decreasing agriculture share are found statistically different on the CO2 emissions, and rising agriculture share in GDP has larger effect than that of decreasing agriculture share. An inverted U-shaped relationship is also found between agriculture share in GDP and CO2 emissions per capita with a turning point at 3.22% agriculture share in GDP.

PS/PANI/MoS2 Hybrid Polymer Composites with High Dielectric Behavior and Electrical Conductivity for EMI Shielding Effectiveness.

Liquid exfoliated molybdenum disulfide (MoS2) nanosheets and polyaniline (PANI) nanoparticles are dispersed in polystyrene (PS) matrix to fabricate hybrid polymer composites with high dielectric and electromagnetic interference (EMI) shielding behavior. A phase-separated morphology is formed when PANI and MoS2 are incorporated into polystyrene (PS) matrix. An increasing concentration of MoS2 nanoparticles inside PS/PANI (5 wt %) polymer blend forms an interconnected network, resulting in high electrical conductivity and dielectric behavior, making them a suitable candidate for EMI shielding application. An increment in dielectric constant and loss, up to four and five orders of magnitude, respectively, is recorded at a maximum concentration of 1 wt % of MoS2 in PS/PANI-5 polymer blend at 100 Hz. The enhanced dielectric characteristics for PS/PANI/MoS2 composites are then theoretically evaluated for the estimation of EMI shielding effectiveness in the frequency range of 100 Hz to 5 MHz. The maximum dielectric constant and loss achieved for PS/PANI-5 wt %/MoS2-1 wt % are responsible for estimated shielding effectiveness of around 92 dB at 100 Hz. The increase in dielectric behavior and shielding effectiveness is probably due to the increased number of charged dipoles accumulated at the insulator-conductor interface.

Probing the effect of various lipids and polymer blends on clopidogrel encapsulated floating microcarriers.

BACKGROUND: Clopidogrel (CLOP) is an antiplatelet drug with poor solubility in intestinal fluid, which limits its bioavailability after oral administration. OBJECTIVES: Current study focuses on developing site-specific floating microcarriers of CLOP using solvent diffusion evaporation method (SDEM) for retaining the drug in the stomach, thus improving the solubility of drug for better absorption. METHODS: SDEM was employed to formulate floating microcarriers using lipidic excipients, namely Gelucires (GL) to impart floating properties, in combination with ethyl cellulose as release retarding polymer. RESULTS: Prepared particles were 169 ± 6 µm to 375 ± 13 µm in size, whilst encapsulation efficiency was ranged from 39.6 ± 0.60% to 96.50 ± 3.50%. Electron micrographs depicted discrete spherical microcarriers with porous structure, which amplified with increasing HLB value of GL and concentration of Eudragit E100. FTIR study confirmed absence of major drug polymer interactions while DSC and XRD studies revealed the presence of non-crystalline nature of drug in all formulations. Drug release at pH 1.2 enhanced more than 2-folds with increasing HLB value with 32% cumulative drug release for GL 43/01 and 69% for GL 50/13. More interestingly, adding various proportions of Eudragit E100 to GL 43/01 based formulations resulted in increased drug release as high as 71%. In all formulations, the drug release followed diffusion dependent process. CONCLUSION: It is envisaged that this formulation strategy for CLOP is promising and could possibly be tested in future for its in vivo performance. Graphical abstract Lipid based floating microcarriers of clopidogrel.

Transoral flexible laryngoscope biopsy: Safety and accuracy.

OBJECTIVE: To determine the accuracy of transoral flexible laryngoscope (TFL) biopsy and also to identify the safety as office based procedure in terms of complications. METHODS: This is a diagnostic study; the type of intervention is outpatient department based biopsy of laryngeal lesions. All patients seen in ENT outpatient department of Lyari General Hospital with suspicious lesions of Larynx were referred for Transoral Flexible Laryngoscopy Biopsy under local anesthesia. The specimens were sent for histopathology. The patients with benign pathology or carcinoma in situ were referred for direct laryngoscopy and biopsy. The sensitivity and specificity were calculated and the frequencies of complications were monitored to determine the complication rate. RESULTS: During the course of study a total of 47 patients underwent TFL biopsy in office settings. Out of these patients 16 patients were referred for direct laryngoscopy biopsy. The study population included 32 men and 15 women with ages ranging from 28 to 52 years and mean of (39 ± 6) years. Among 43 patients squamous cell carcinoma was the final diagnosis in 31 patients. In the rest of 12 patients' dysplasia and benign lesion was the diagnosis in 9 and 3 patients respectively. These 12 patients underwent direct laryngoscopy biopsy and 10 of them diagnosed with invasive carcinoma rest had benign lesions. Hence the specificity was 75.6% and sensitivity was 100%. None of the patients developed any serious complication. CONCLUSIONS: All patients with a suspicious lesion diagnosed by TFL biopsy as being benign or carcinoma in situ should have direct laryngoscopy for verification of the findings. But the results positive for carcinoma are reliable. In addition, this is a safe procedure.

Efficacy of Empirical Therapy With Combined Ciprofloxacin Versus Topical Drops Alone in Patients With Tubotympanic Chronic Suppurative Otitis Media: A Randomized Double-Blind Controlled Trial.

BACKGROUND: One of the prevailing otologic infections in our country is chronic suppurative otitis media, especially the tubotympanic type for which various treatment protocols are followed. Usually, oral and topical antibiotics (mainly quinolones) are given alone or in combination. There is a lack of consensus as to whether topical drops alone are effective or a combined oral and systemic therapy should be prescribed. In our study, we have attempted to observe the efficacy of empirical therapy with combined ciprofloxacin versus topical drops only in patients with tubotympanic chronic suppurative otitis media for control of infection. METHODOLOGY: A total of 100 patients visiting the outpatient ENT department at our tertiary care hospital with clinically diagnosed chronic suppurative otitis media (tubotympanic type) were enrolled in our study. The study was reviewed and accepted by the ethical review committee. A detailed proforma was filled for all patients. All patients after aural toilet were subjected randomly to one of the 2 treatment methods, ie, topical ciprofloxacin ear drops plus an oral placebo or combined oral and topical ciprofloxacin. These patients were reviewed after 1 week of treatment. RESULTS: It was observed that 48 of 50 (96%) patients responded to treatment in the group receiving topical ciprofloxacin, whereas 49 of 50 (98%) patients responded in the group receiving combined therapy. This difference was not significant. Moreover, age, sex, and duration of discharge did not have any effect on treatment. There were minimal side effects in both groups, which were also not significant and disappeared after discontinuation of treatment. CONCLUSIONS: The results of this study show that topical ciprofloxacin drops were as effective as combined oral and topical ciprofloxacin and that the addition of oral drug did not have any beneficial effect and added only to the cost of treatment.

Preservation of Hearing and Facial Nerve Function with the Microsurgical Excision of Large Vestibular Schwannomas: Experience with the Retrosigmoid Approach.

Introduction Vestibular schwannomas (VS) are the most common benign neoplasms of a cerebellopontine angle (CPA), which arise from the Schwann cells of the vestibulocochlear nerve. Eighty percent of CPA tumors are VS followed by meningioma as the second common mass lesion in this critical potential space. Treatment options range from watchful waiting with serial imaging studies to radiosurgery or a microsurgical excision or a combination of surgery and radiation therapy. The primary objective of the study was to assess hearing and facial nerve status before and after the surgery via the retrosigmoid approach. Methods The database of Aga Khan University Hospital was searched for diagnoses of vestibular schwannomas between 2000 and 2007. A total of 35 patients were identified; among them, 27 were selected for the study who met the inclusion criteria. The variables of the study were age, gender, presenting symptoms, size of the tumor, surgical approach, hearing levels, and facial nerve function. Hearing loss was categorized according to the Gardener-Robertson hearing classification and the House-Brackmann Scale was used for facial nerve assessment. Results Out of the 27 patients, 18 were male and nine were female. The mean age was 43 years. The most common presenting complaint was hearing loss and tinnitus, seen in 21 patients. Headache was present in six patients, ataxia in five, and vertigo in three. Facial nerve weakness was noticed in six patients. Two patients had Grade-III paralysis, three had Grade-IV paralysis, and one had Grade-V paralysis. The audiogram confirmed the presence of sensorineural hearing loss (SNHL) in all patients. Twelve patients out of 27 had Class II hearing with the threshold between 31 and 50 decibels and a Speech Discrimination Score (SDS) of 50% to 69%. Ten patients had non-serviceable hearing and the remaining five had poor hearing. The audiogram was repeated after surgery for those 12 patients who had Class II hearing and showed that seven out of 12 patients maintained a hearing threshold within the range of Class II at the one-year follow-up (hearing preservation 58%). The facial nerve preservation rate was 56% considering House-Brackmann Grade III or less as acceptable facial nerve function. Conclusion The optimal treatment for small vestibular schwannomas is a matter of controversy; however, the choice of treatment for large vestibular schwannomas in patients without significant comorbidity is generally microsurgical excision. The surgical excision of a large VS with the retrosigmoid approach is found to be safe consistently. The hearing and facial nerve preservation in our study were found comparable with the literature.

Proniosomes derived niosomes: recent advancements in drug delivery and targeting.

Vesicular drug delivery systems have gained wide attention in the field of nanotechnology. Among them proniosomes become the superior over other vesicular carriers. Proniosomes are dry formulations of water soluble nonionic surfactant coated carrier system which immediately forms niosomes upon hydration. They have the capability to overcome the instability problems associated with niosomes and liposomes and have the potential to improve solubility, bioavailability, and absorption of various drugs. Furthermore, they offer versatile drug delivery concept for enormous number of hydrophilic and hydrophobic drugs. They have the potential to deliver drugs effectively through different routes at specific site of action to achieve controlled release action and reduce toxic effects associated with drugs. This review discusses the general preparation techniques of proniosomes and mainly focus on the applications of proniosomes in drug delivery and targeting. Moreover, this review demonstrates critical appraisal of the literature for proniosomes. Additionally, this review extensively explains the potential of proniosomes in delivering drugs via different routes, such as oral, parenteral, dermal and transdermal, ocular, oral mucosal, vaginal, pulmonary, and intranasal. Finally, the comparison of proniosomes with niosomes manifests the clear distinction between them. Moreover, proniosomes need to be explored for proteins and peptide delivery and in the field of nutraceuticals and develop pilot plant scale up studies to investigate them in industrial set up.

Enhanced mechanical properties and biocompatibility of novel hydroxyapatite/TOPAS hybrid composite for bone tissue engineering applications.

The bioactivity and mechanical properties of hybrid composites of hydroxyapatite (HA) in cyclic olefinic copolymer (COC) also known commercially as TOPAS are investigated, first time, for regeneration and repair of the bone tissues. HA is synthesized to obtain the spherically shaped nanoparticles in the size range of 60±20nm. Various concentrations of HA ranging from 1 to 30wt% are dispersed in TOPAS using sodium dodecyl sulfate (SDS) coupling agent for better dispersion and interaction of hydrophilic HA with hydrophobic TOPAS. Scanning electron microscope shows the uniform dispersion of HA≤10wt% in TOPAS and at higher concentrations >10wt%, agglomeration occurs in the hybrid composites. Tunable mechanical properties are achieved as the compressive modulus and strength are increased around 140% from 6.4 to 15.3MPa and 185% from 0.26 to 0.74MPa, respectively. Such increase in the mechanical properties of TOPAS is attributed to the anchoring of the polymer chains in the vicinity of HA nanoparticles owing to better dispersion and interfacial interactions. In comparison to neat TOPAS, hybrid composites of TOPAS/HA promoted the cell adhesion and proliferation significantly. The cell density and proliferation of TOPAS/HA hybrid composites is enhanced 9 and 3 folds, respectively, after 1day culturing in preosteoblasts cells. Moreover, the morphology of cells changed from spherical to flattened spread morphology demonstrating clearly the migration of the cells for the formation of interconnected cellular network. Additionally, very few dead cells are found in hybrid composites showing their cytocompatibility. Overall, the hybrid composites of TOPAS/HA exhibited superior strength and stiffness along with enhanced cytocompatibility for bone tissue engineering applications.