A unique case of bilateral nanophthalmos and pigmentary retinal abnormality with unilateral angle closure glaucoma and optic disc pit.

BACKGROUND: Microophthalmos or 'dwarf eye' is characterized by an axial length 2 standard deviation less than age-matched controls. It is classified into nanophthalmos, relative anterior microphthalmos, and posterior microphthalmos based on the anterior segment: posterior segment ratio. Nanophthalmos can occur in association with optic disc drusen, foveoschisis, and retinitis pigmentosa, as an autosomal recessive syndrome linked to mutations in the MFRP gene. We report a case of bilateral nanophthalmos and pigmentary retinopathy with angle closure glaucoma and optic disc pit in one eye. We believe this to be the first case presenting with optic disc pit in association with nanophthalmos. CASE PRESENTATION: A 56-year-old female presented with bilateral small eyes, high hypermetropia, shallow anterior chamber depth, increased lens thickness, mid-peripheral retinal flecks, and macular edema. She also had high intraocular pressure in the right eye, with a disc cupping of 0.9 with an Optic disc pit. The macular edema in the right eye was found to occur in association with the Optic disc pit, whereas, in the left eye, it was associated with intra-retinal hemorrhages and diagnosed as macular branch retinal vein occlusion secondary to hypertension. She was started on anti-glaucoma medications in both eyes and planned for Anti-VEGF injection in the left eye. CONCLUSION: This case report is unique as it reports an association of Nanophthalmos with Optic Disc pit, with an associated angle closure glaucoma in the same eye, an association which has never been previously reported in the literature.

Cyclooxygenase 2 and vascular endothelial growth factor-potential targets to manage lepra reactions: A case-control study.

Reactions in leprosy have an immune mediated pathogenesis. While type 1 reactions are delayed hypersensitivity phenomenon, type 2 reactions are immune complex mediated. Key molecules which mediate the immune insult in lepra reactions require evaluation in order to tailor their therapy and prevent disability. The objective of the study was to evaluate expressions of Cyclooxygenase 2 and Vascular Endothelial Growth Factor in skin biopsies from leprosy patients and correlate their expression with presence of either type 1 or type 2 lepra reactions. This was a case control study. Cyclooxygenase 2 and Vascular Endothelial Growth Factor expression in dermal macrophages and vascular endothelium was assessed immunohistochemically. Biopsies from patients with Non-reactive leprosy and healthy controls were used for comparison. SPSS software was used for statistical analysis. A total of 147 skin biopsies were evaluated, including 18 with Type 1 reaction, 39 Type 2 reaction, 81 non-reactive leprosy and 9 healthy controls. Both Cyclooxygenase 2 and Vascular Endothelial Growth Factor expression were significantly higher in type 1 followed by type 2 reaction as compared to controls. These results may guide us regarding use of Cyclooxygenase 2 and Vascular Endothelial Growth Factor inhibitor drugs which may be a major step in treating reactive leprosy patients and preventing nerve damage and disability.

Chromosomal aneuploidies induced upon Lamin B2 depletion are mislocalized in the interphase nucleus.

Chromosome territories assume non-random positions in the interphase nucleus with gene-rich chromosomes localized toward the nuclear interior and gene-poor chromosome territories toward the nuclear periphery. Lamins are intermediate filament proteins of the inner nuclear membrane required for the maintenance of nuclear structure and function. Here, we show using whole-genome expression profiling that Lamin A/C or Lamin B2 depletion in an otherwise diploid colorectal cancer cell line (DLD1) deregulates transcript levels from specific chromosomes. Further, three-dimensional fluorescence in situ hybridization (3D-FISH) analyses of a subset of these transcriptionally deregulated chromosome territories revealed that the diploid chromosome territories in Lamin-depleted cells largely maintain conserved positions in the interphase nucleus in a gene-density-dependent manner. In addition, chromosomal aneuploidies were induced in ~25 % of Lamin A/C or Lamin B2-depleted cells. Sub-populations of these aneuploid cells consistently showed a mislocalization of the gene-rich aneuploid chromosome 19 territory toward the nuclear periphery, while gene-poor aneuploid chromosome 18 territory was mislocalized toward the nuclear interior predominantly upon Lamin B2 than Lamin A/C depletion. In addition, a candidate gene locus ZNF570 (Chr.19q13.12) significantly overexpressed upon Lamin B2 depletion was remarkably repositioned away from the nuclear lamina. Taken together, our studies strongly implicate an overarching role for Lamin B2 in the maintenance of nuclear architecture since loss of Lamin B2 relieves the spatial positional constraints required for maintaining conserved localization of aneuploid chromosome territories in the interphase nucleus.

Molecular and cellular roles of PI31 (PSMF1) protein in regulation of proteasome function.

We investigated molecular features and cellular roles of PI31 (PSMF1) on regulation of proteasome function. PI31 has a C-terminal HbYX (where Hb is a hydrophobic amino acid, Y is tyrosine, and X is any amino acid) motif characteristic of several proteasome activators. Peptides corresponding to the PI31 C terminus also bind to and activate the 20 S proteasome in an HbYX-dependent manner, but intact PI31protein inhibits in vitro 20 S activity. Binding to and inhibition of the proteasome by PI31 are conferred by the HbYX-containing proline-rich C-terminal domain but do not require HbYX residues. Thus, multiple regions of PI31 bind independently to the proteasome and collectively determine effects on activity. PI31 blocks the ATP-dependent in vitro assembly of 26 S proteasome from 20 S proteasome and PA700 subcomplexes but has no effect on in vitro activity of the intact 26 S proteasome. To determine the physiologic significance of these in vitro effects, we assessed multiple aspects of cellular proteasome content and function after altering PI31 levels. We detected no change in overall cellular proteasome content or function when PI31 levels were either increased by moderate ectopic overexpression or decreased by RNA interference (RNAi). We also failed to identify a role of PI31 ADP-ribosylation as a mechanism for regulation of overall 26 S proteasome content and function, as recently proposed. Thus, despite its in vitro effects on various proteasome activities and its structural relationship to established proteasome regulators, cellular roles and mechanisms of PI31 in regulation of proteasome function remain unclear and require future definition.

Choroidal thickness in thyroid eye disease and its correlation with disease activity.

CONTEXT: This study adds to the existing body of literature on the role of optical coherence tomography (OCT) parameters in active thyroid eye disease (TED) among the Indian population. PURPOSE: Comparison of choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in active and inactive TED. SETTINGS AND DESIGN: An observational, cross-sectional analytical study conducted at a tertiary eye care hospital in North India that included patients with active and inactive TED. METHODS: Demographic details and clinical evaluation were performed for all TED patients. SFCT was determined with OCT by using the Cirrus linear measurement tool. CVI was calculated using Image J software. The SFCT and CVI measurements were compared between both groups. STATISTICAL ANALYSIS USED: Comparison between active and inactive TED groups was done using Mann-Whitney U test for non-parametric data and Student t test for parametric data. Multivariate regression analysis was performed with SFCT and CVI as dependent variables. RESULTS: Sixty-two eyes of 31 patients were included. Thirteen eyes had active TED, and 49 eyes had inactive TED. SFCT was significantly lower in eyes with higher clinical activity score (CAS) and older age. No significant difference was found in CVI between active and inactive TED eyes. CONCLUSION: SFCT was lower in eyes with higher CAS and older age. Our findings differ from previous studies, which showed a positive correlation between SFCT and CAS. There was no significant difference in CVI between active and inactive TED eyes.

Microbial strategies for copper pollution remediation: Mechanistic insights and recent advances.

Environmental contamination is aninsistent concern affecting human health and the ecosystem. Wastewater, containing heavy metals from industrial activities, significantly contributes to escalating water pollution. These metals can bioaccumulate in food chains, posing health risks even at low concentrations. Copper (Cu), an essential micronutrient, becomes toxic at high levels. Activities like mining and fungicide use have led to Copper contamination in soil, water, and sediment beyond safe levels. Copper widely used in industries, demands restraint of heavy metal ion release into wastewater for ecosystem ultrafiltration, membrane filtration, nanofiltration, and reverse osmosis, combat heavy metal pollution, with emphasis on copper.Physical and chemical approaches are efficient, large-scale feasibility may have drawbackssuch as they are costly, result in the production of sludge. In contrast, bioremediation, microbial intervention offers eco-friendly solutions for copper-contaminated soil. Bacteria and fungi facilitate these bioremediation avenues as cost-effective alternatives. This review article emphasizes on physical, chemical, and biological methods for removal of copper from the wastewater as well asdetailing microorganism's mechanisms to mobilize or immobilize copper in wastewater and soil.

E1-E2 interactions in ubiquitin and Nedd8 ligation pathways.

Initial rates of E1-catalyzed E2 transthiolation have been used as a reporter function to probe the mechanism of 125I-ubiquitin transfer between activation and ligation half-reactions of ubiquitin conjugation. A functional survey of 11 representative human E2 paralogs reveals similar Km for binding to human Uba1 ternary complex (Km(ave)=121±72 nm) and kcat for ubiquitin transfer (kcat(ave)=4.0±1.2 s(-1)), suggesting that they possess a conserved binding site and transition state geometry and that they compete for charging through differences in intracellular concentration. Sequence analysis and mutagenesis localize this binding motif to three basic residues within Helix 1 of the E2 core domain, confirmed by transthiolation kinetics. Partial conservation of the motif among E2 paralogs not recognized by Uba1 suggests that another factor(s) account for the absolute specificity of cognate E2 binding. Truncation of the Uba1 carboxyl-terminal ß-grasp domain reduces cognate Ubc2b binding by 31-fold and kcat by 3.5×10(4)-fold, indicating contributions to E2 binding and transition state stabilization. Truncation of the paralogous domain from the Nedd8 activating enzyme has negligible effect on cognate Ubc12 transthiolation but abrogates E2 specificity toward non-cognate carrier proteins. Exchange of the ß-grasp domains between ubiquitin and Nedd8 activating enzymes fails to reverse the effect of truncation. Thus, the conserved Helix 1 binding motif and the ß-grasp domain direct general E2 binding, whereas the latter additionally serves as a specificity filter to exclude charging of non-cognate E2 paralogs in order to maintain the fidelity of downstream signaling.

Integrating Electrochemical CO2 Reduction on α-NiS with the Water or Organic Oxidations by Its Electro-Oxidized NiO(OH) Counterpart to an Artificial Photosynthetic Scheme.

Efficient hydrogen production, biomass up-conversion, and CO2-to-fuel generation are the key challenges of the present decade. Electrocatalysis in aqueous electrolytes by choosing suitable transition-metal-based electrode materials remains the green approach for the trio of sustainable developments. Given that, finding electrode materials with multifunctional capability would be beneficial. Herein, the nanocrystalline α-NiS, synthesized solvothermally, has been chosen as an electrode material. As the first step to construct an electrolyzer, α-NiS deposited on conducting nickel foam (NF) has been used as an anode, and under the anodic potential, the α-NiS particles have lost sulfides to the electrolyte and transform to amorphous electro-derived NiO(OH) (NiO(OH)ED), confirmed by different spectroscopic and microscopic studies. In situ transformation of α-NiS to amorphous NiO(OH)ED results in an enhancement of the electrochemical surface area and not only becomes active toward oxygen evolution reaction (OER) at a moderate overpotential of 264 mV (at 20 mA cm-2) but also can convert a series of biomass-derived organic compounds, namely, 2-hydroxymethylfurfural (HMF), 2-furfural (FF), ethylene glycol (EG), and glycerol (Gly), to industrially relevant feedstocks with a high (∼96%) Faradaic efficiency. During these organic oxidations, NiO(OH)ED/NF participate in the multiple-electron oxidation process (up to 8e-) including C-C bond cleavages of EG and Gly. During the cathodic performance of the α-NiS/NF, the structural integrity has been retained and the unaltered α-NiS/NF electrode remains more effective cathode for alkaline hydrogen evolution reaction (HER) and CO2 reduction (CO2R) compared to its in situ-derived NiO(OH)ED/NF. α-NiS/NF can reduce the CO2 predominantly to CO even at a higher potential like -0.8 V (vs RHE). The fabricated cell with α-NiS and its electro-oxidized NiO(OH)ED counterpart, α-NiS/NF(-)/(+)NiO(OH)ED/NF, is able to show an artificial photosynthetic scheme in which the NiO(OH)ED/NF anode oxidizes water to O2 and the α-NiS cathode reduces CO2 majorly to CO in a moderate cell potential. In this study, α-NiS has been utilized as a single electrode material to perform multiple sustainable transformations.

Recent advancement of HDAC inhibitors against breast cancer.

Recent studies highlight the great potential impact of HDAC inhibitors (HDACis) in suppressing TNBC, even though clinical trials including a single HDACis demonstrated unsatisfactory outcomes against TNBC. New compounds created to achieve isoform selectivity and/or a polypharmacological HDAC strategy have also produced interesting results. The current study discusses the HDACis pharmacophoric models and the structural alterations that produced drugs with strong inhibitory effects on TNBC progression. With more than 2 million new cases reported in 2018, breast cancer-the most common cancer among women worldwide-poses a significant financial burden on an already deteriorating public health system. Due to a lack of therapies being developed for triple-negative breast cancers and the development of resistance to the current treatment options, it is imperative to plan novel therapeutics in order to bring new medications to the pipeline. Additionally, HDACs deacetylate a large number of nonhistone cellular substrates that control a variety of biological processes, such as the beginning and development of cancer. The significance of HDACs in cancer and the therapeutic potential of HDAC inhibitor. Furthermore, we also reported molecular docking study with four HDAC inhibitors and performed molecular dynamic stimulation of the best dock score compound. Among the four ligands belinostat compound showed best binding affinity with histone deacetylase protein which was -8.7 kJ/mol. It also formed five conventional hydrogen bond with Gly 841, His 669, His 670, pro 809, and His 709 amino acid residues.

Role and Recent Advancements of Ionic Liquids in Drug Delivery Systems.

Advancements in the fields of ionic liquids (ILs) broaden its applications not only in traditional use but also in different pharmaceutical and biomedical fields. Ionic liquids "Solutions for Your Success" have received a lot of interest from scientists due to a myriad of applications in the pharmaceutical industry for drug delivery systems as well as targeting different diseases. Solubility is a critical physicochemical property that determines the drug's fate at the target site. Many promising drug candidates fail in various phases of drug research due to poor solubility. In this context, ionic liquids are regarded as effective drug delivery systems for poorly soluble medicines. ILs are also able to combine different anions/cations with other cations/anions to produce salts that satisfy the concept behind the ILs. The important characteristics of ionic liquids are the modularity of their physicochemical properties depending on the application. The review highlights the recent advancement and further applications of ionic liquids to deliver drugs in the pharmaceutical and biomedical fields.

Two novel bioactive glucosinolates from Broccoli (Brassica oleracea L. var. italica) florets.

Two novel glucosinolates along with one known glucosinolate were isolated from Broccoli (Brassica oleracea L. var. italica) florets. Their structures were established mainly by 1D ((1)H and (13)C NMR), 2D NMR ((1)H-(1)H COSY, DEPT 135°, HSQC and HMBC), and Tandem MS-MS spectrometric data as 2-mercaptomethyl sulfinyl glucosinolate [(Z)-4-(methylsulfinyl)-N-(sulfooxy)-2-((2'S,3'R,4'S,5'S,6'R)-3',4',5'-trihydroxy-6'(hydroxylmethyl)-2'-mercapto tetrahydro-2H-pyran-2-yl) butane amide] 1, (Z)-1-((2S,5S)-5-hydroxytetra-hydro-2H-pyran-2-ylthio)-2-(1H-indol-3-yl) ethylidene amino sulfate 2 and a known cinnamoyl [6'-O-trans-(4″-hydroxy cinnamoyl)4-(methylsulphinyl)butyl glucosinolate] 3. Compound 1 exhibited scavenging activity against DPPH with an inhibitory concentration IC(50) of 20 mM, whereas compound 3 was a weak antioxidant when compared to the standard quercetin (5 mM) as a positive control. Both the compounds showed a significant and similar antimicrobial activity against Staphylococcus aureus with an IC(50) of <625 µg/mL when compared to antibiotic duricef. Against Salmonella typhimurium the IC(50) of 1 and 3 was determined as <625 µg/mL and <1250 µg/mL, respectively, when compared to ampicillin (IC(50) ≤ 39 µg/mL) as a positive control.

Fusarium Causing Recalcitrant Post-operative endophthalmitis-Report of a Case with Review of Literature.

PURPOSE: To study the clinical profile and management of a case of fungal postoperative endophthalmitis caused by fusarium solani. CASE REPORT: A 40-year-old male underwent an uneventful cataract surgery developed postoperative endophthalmitis. The infection was fulminant and was treated aggressively with pars plana vitrectomy with intravitreal and oral antifungals. The microbiology culture of vitreous sample showed fusarium solani. There was a late recurrence in the form of a fungal ball behind the iris after 6 months of the initial episode. This fungal ball was then managed by transscleral cryotherapy. The eye became hypotonus due to chronic inflammation and silicone oil was instilled to salvage the eye. CONCLUSION: Fusarium endophthalmitis needs an aggressive management. Due to late recurrence regular follow-up is mandatory. Early vitrectomy with oral and intravitreal voriconazole is the treatment of choice. Transscleral cryotherapy is a useful option to treat fungal balls behind the iris tissue.

Honeybee pollen assisted biosynthesis of nanogold and its application as catalyst in reduction of 4-nitrophenol.

Nowadays, the exploration of natural materials for the production of nanoparticles is of special interest due to its ecofriendly nature. In this paper, we presented the biosynthesis of gold nanoparticles (AuNPs) in a green route by using water extract of pollen from Andean honeybees. Furthermore, AuNPs have been characterized by various techniques and tested for the catalytic reduction of 4-nitrophenol (4-NP). The biosynthesized AuNPs were analyzed using UV-vis spectroscopy, Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) spectroscopy to confirm their optical properties, stability, surface morphology, and purity. The synthesized AuNPs proved to be well dispersed, spherical, and triangular in shape, with particle sizes ranging from 7 to 42 nm having λmax at 530 nm. Moreover, FTIR suggests the capping of AuNPs with pollen constituents and XRD confirms the crystalline structure of AuNPs. Additionally, prepared AuNPs were demonstrated to be effective in reducing organic pollutant 4-NP to 4-aminophenol (k = 59.17898 × 10-3 min-1, R2 = 0.994). All of these studies have emphasized that AuNPs production can be scale up by using naturally available pollen grains and open up a new perspective for beekeepers.

Tubercular Osteomyelitis of the Orbit Presenting as Periorbital Cellulitis.

PURPOSE: Osteomyelitis of the orbital bones presenting as an orbital cellulitis is a rare form of extrapulmonary tuberculosis (TB). We report a rare case of tubercular osteomyelitis of the orbital bones presenting as a periorbital cellulitis. CASE REPORT: A seven-year-old female child presented to our tertiary eye care center with swelling involving the right eyelids and the right cheek for two months. She had been provisionally diagnosed elsewhere as pre-septal cellulitis and had been given oral antibiotics. We clinically diagnosed her as orbital cellulitis, but her non-responsiveness to intravenous antibiotics prompted us to get a contrast enhanced computed tomography (CECT) of the orbit and paranasal sinuses, which was suggestive of tubercular etiology. However, the patient had no foci for TB elsewhere. We used a relatively new, but rapid test, called Cartridge-based Nucleic Acid Amplification Test (CBNAAT) on the pus aspirate which was positive for TB. Thereafter, the patient was started on anti-tubercular treatment to which she responded wonderfully. CONCLUSION: A high index of suspicion should be kept for TB infection in cases of orbital cellulitis with unusual clinical behavior in an endemic region such as India.

Assessment of Kidney Involvement in COVID-19 Patient.

BACKGROUND AND AIM: Physicians need to be aware of the difficulties that SARS-CoV-2 infection brings to other regions of the body, such as the kidneys, even though the key emphasis is on pulmonary characteristics. The most frequent kidney complication among COVID-19 hospitalized patients is considered acute kidney injury (AKI). This study aimed to describe overall different aspects of acute kidney injury (AKI) in COVID-19 patients admitted to JLNMCH during the COVID-19 pandemic and to determine the prevalence of AKI among COVID-19 hospitalized patients. METHODS AND MATERIALS: All adult patients (over the age of 18 years) who screened positive for COVID-19 in a swab specimen from areas of nasopharyngeal by reverse transcriptase polymerase chain reaction and then hospitalized were included in the study. Information was gathered on the patient's demographics, general medical history, and drugs prescribed. From past medical information, associated comorbidities and home pharmaceuticals were identified. We gathered hospitalization information, such as duration of stay in ICU, details about the application of mechanical ventilation, information regarding extracorporeal membrane aeration, details of the use of vasopressor administration, and baseline results of laboratory test along with baseline clinical information during 48 hours of hospitalization. RESULTS: The percentage of patients with no history of AKI requiring traumatic mechanical ventilation was 79.4%, while the percentage of patients with no history of AKI not requiring traumatic mechanical ventilation was 11.5%. The difference was relevant statistically (p<0.001). The percentage of patients with AKI of any stage requiring traumatic mechanical ventilation was 22.8%, while the percentage of patients with no history of AKI not requiring traumatic mechanical ventilation was 76.8%. The difference was relevant statistically (p<0.022). CONCLUSION: We discovered that AKI was a rather typical finding among hospitalized COVID-19 patients. Patients hospitalized for COVID-19 had a poor prognosis if they developed AKI.

Correlation between choroidal thickness and intraocular pressure control in primary angle-closure glaucoma.

PURPOSE: To study the correlation between choroidal thickness (CT) and IOP control in primary angle-closure glaucoma (PACG). METHODS: In total, 61 patients (102 eyes) with PACG underwent subfoveal CT (SFCT) scanning using enhanced depth imaging-optical coherence tomography. The subjects with PACG were further grouped as controlled IOP (≤21 mm Hg on maximal medical therapy) and uncontrolled IOP (>21 mm Hg on maximal medical therapy). The average CT of the PACG eyes was calculated and compared between both groups. A correlation analysis was done between CT and intereye difference in CT with the disease parameters. RESULTS: The mean CT was 274.38 ± 42.10 µm in 102 PACG eyes. SFCT was significantly increased in the uncontrolled IOP group as compared with the controlled IOP group. The mean SFCT was 245.57 ± 62.10 µm in the controlled group and 294.46 ± 51.05 µm in the uncontrolled group (P < 0.01). Factors associated with a thicker choroid were younger age, high IOP, and higher optic nerve head cupping (P < 0.001). Neither the visual field-mean deviation (VF-MD) nor pattern standard deviation (PSD) was found to be associated with overall CT. The intereye asymmetry between CT was significantly associated with poor VF-MD and PSD. CONCLUSION: PACG eyes with thicker choroid may be a risk factor for poor IOP control on medical anti-glaucoma therapy. Thicker choroid as compared to the fellow eye is a poor prognostic sign and these eyes should be monitored closely.

A comparison of sutureless flanged fixation and 4-point Gore-Tex fixation for scleral-fixated intraocular lenses: a pilot study.

Purpose: Scleral-fixation of intraocular lenses (IOLs) provides an option for eyes that lack sufficient capsular support for in-the-bag IOL placement. The latest techniques for lens fixation include use of a novel suture material, Gore-Tex, and a sutureless method, with flanged intrascleral fixation. The purpose of this pilot study was to compare these methods in terms of anatomic and clinical outcomes. Methods: A total of 35 eyes of patients 18-60 years of age who presented with aphakia, subluxated lens, or ectopia lentis were randomized into two groups. Group A (15 eyes) underwent flanged intrascleral IOL fixation using the Yamane technique; group B (20 eyes) underwent 4-point transscleral fixation of IOL using Gore-Tex suture. The following parameters were compared between groups on day 1, week 3, and month 6 postoperatively: logMAR uncorrected and best-corrected visual acuity, retinoscopy, IOL centration on slit-lamp biomicroscopy, and IOL tilt on ultrasound biomicroscopy. Results: Postoperative visual acuity was better in group B: uncorrected, logMAR 0.89 ± 0.22 versus 0.72 ± 0.24 (P = 0.046); best-corrected, logMAR 0.51 ± 0.18 versus 0.37 ± 0.26 (P = 0.016). No significant difference was found in postoperative retinoscopy and astigmatism between groups. IOL tilt (>100 µm) occurred in 8 cases in group A and in 9 cases in group B; 87% in group A and 100% in group B were well centered. Complications in both groups were minimal. Conclusions: In our small study cohort, both sutureless flanged IOL fixation and Gore-Tex sutured scleral IOL fixation resulted in excellent visual rehabilitation of patients with aphakia and subluxated lenses. Patients who underwent Gore-Tex suture fixation experienced better postoperative visual acuity, IOL centration, and stability.

Comparative statistical analysis of the release kinetics models for nanoprecipitated drug delivery systems based on poly(lactic-co-glycolic acid).

Poly(lactic-co-glycolic acid) is one of the most used polymers for drug delivery systems (DDSs). It shows excellent biocompatibility, biodegradability, and allows spatio-temporal control of the release of a drug by altering its chemistry. In spite of this, few formulations have reached the market. To characterize and optimize the drug release process, mathematical models offer a good alternative as they allow interpreting and predicting experimental findings, saving time and money. However, there is no general model that describes all types of drug release of polymeric DDSs. This study aims to perform a statistical comparison of several mathematical models commonly used in order to find which of them best describes the drug release profile from PLGA particles synthesized by nanoprecipitation method. For this purpose, 40 datasets extracted from scientific articles published since 2016 were collected. Each set was fitted by the models: order zero to fifth order polynomials, Korsmeyer-Peppas, Weibull and Hyperbolic Tangent Function. Some data sets had few observations that do not allow to apply statistic test, thus bootstrap resampling technique was performed. Statistic evidence showed that Hyperbolic Tangent Function model is the one that best fit most of the data.

The C terminus of Rpt3, an ATPase subunit of PA700 (19 S) regulatory complex, is essential for 26 S proteasome assembly but not for activation.

PA700, the 19 S regulatory subcomplex of the 26 S proteasome, contains a heterohexameric ring of AAA subunits (Rpt1 to -6) that forms the binding interface with a heteroheptameric ring of α subunits (α1 to -7) of the 20 S proteasome. Binding of these subcomplexes is mediated by interactions of C termini of certain Rpt subunits with cognate binding sites on the 20 S proteasome. Binding of two Rpt subunits (Rpt2 and Rpt5) depends on their last three residues, which share an HbYX motif (where Hb is a hydrophobic amino acid) and open substrate access gates in the center of the α ring. The relative roles of other Rpt subunits for proteasome binding and activation remain poorly understood. Here we demonstrate that the C-terminal HbYX motif of Rpt3 binds to the 20 S proteasome but does not promote proteasome gating. Binding requires the last three residues and occurs at a dedicated site on the proteasome. A C-terminal peptide of Rpt3 blocked ATP-dependent in vitro assembly of 26 S proteasome from PA700 and 20 S proteasome. In HEK293 cells, wild-type Rpt3, but not Rpt3 lacking the HbYX motif was incorporated into 26 S proteasome. These results indicate that the C terminus of Rpt3 was required for cellular assembly of this subunit into 26 S proteasome. Mutant Rpt3 was assembled into intact PA700. This result indicates that intact PA700 can be assembled independently of association with 20 S proteasome and thus may be a direct precursor for 26 S proteasome assembly under normal conditions. These results provide new insights to the non-equivalent roles of Rpt subunits in 26 S proteasome function and identify specific roles for Rpt3.

Ser(120) of Ubc2/Rad6 regulates ubiquitin-dependent N-end rule targeting by E3{alpha}/Ubr1.

In CHO cells, CDK1/2-dependent phosphorylation of Ubc2/Rad6 at Ser(120) stimulates its ubiquitin conjugating activity and can be replicated by a S120D point mutant (Sarcevic, B., Mawson, A., Baker, R. T., and Sutherland, R. L. (2002) EMBO J. 21, 2009-2018). In contrast, we find that ectopic expression of wild type Ubc2b but not Ubc2bS120D or Ubc2bS120A in T47D human breast cancer cells specifically stimulates N-end rule-dependent degradation but not the Ubc2-independent unfolded protein response pathway, indicating that the former is E2 limiting in vivo and likely down-regulated by Ser(120) phosphorylation, as modeled by the S120D point mutation. In vitro kinetic analysis shows the in vivo phenotype of Ubc2bS120D and Ubc2bS120A is not due to differences in activating enzyme-catalyzed E2 transthiolation. However, the Ser(120) mutants possess marked differences in their abilities to support in vitro conjugation by the N-end rule-specific E3α/Ubr1 ligase that presumably accounts for their in vivo effects. Initial rate kinetics of human E3α-catalyzed conjugation of the human α-lactalbumin N-end rule substrate shows Ubc2bS120D is 20-fold less active than wild type E2, resulting from an 8-fold increase in K(m) and a 2.5-fold decrease in V(max), the latter reflecting a decreased ability to support the initial step in target protein conjugation; Ubc2bS120A is 8-fold less active than wild type E2 due almost exclusively to a decrease in V(max), reflecting a defect in polyubiquitin chain elongation. These studies suggest a mechanism for the integrated regulation of diverse ubiquitin-dependent signaling pathways through E2 phosphorylation that yields differential effects on its cognate ligases.