Cationic nanoemulsions as potential carriers for intracellular delivery.

Successful cytosolic delivery enables opportunities for improved treatment of various genetic disorders, infectious diseases and cancer. Cationic nanoemulsions were designed using alternative excipients and evaluated for particle size, charge, effect of sterilization on its stability, DNA condensation potential and cellular uptake efficiency. Various concentrations of non-ionic and ionic stabilizers were evaluated to design formula for colloidally stable cationic nanoemulsion. The nanoemulsion comprised of 5% Capmul MCM, 0.5% didodecyldimethylammonium bromide (DDAB), 1% phospholipid, 1% Poloxamer 188 and 2.25% glycerol and possessed particle size of 81.6 ± 3.56 nm and 137.1 ± 1.57 nm before and after steam sterilization, respectively. DNA condensation studies were carried out at various nanoemulsion: DNA ratios ranging from 1:1 to 10:1. Cell uptake studies were conducted on human embryonic kidney (HEK) cell lines which are widely reported for transfection studies. The nanoemulsions showed excellent cellular uptake as evaluated by fluorescence microscopy and flow cytometry. Overall, a colloidally stable cationic nanoemulsion with good DNA condensation ability was successfully fabricated for efficient cytosolic delivery and potential for in vivo effectiveness.

Coherent backscattering of ultracold atoms.

We report on the direct observation of coherent backscattering (CBS) of ultracold atoms in a quasi-two-dimensional configuration. Launching atoms with a well-defined momentum in a laser speckle disordered potential, we follow the progressive build up of the momentum scattering pattern, consisting of a ring associated with multiple elastic scattering, and the CBS peak in the backward direction. Monitoring the depletion of the initial momentum component and the formation of the angular ring profile allows us to determine microscopic transport quantities. We also study the time evolution of the CBS peak and find it in fair agreement with predictions, at long times as well as at short times. The observation of CBS can be considered a direct signature of coherence in quantum transport of particles in disordered media. It is responsible for the so called weak localization phenomenon, which is the precursor of Anderson localization.

An analytical technique for measuring protein carbonyl in the stratum corneum using surface plasmon resonance.

Protein carbonyl groups in the stratum corneum may be used as a biomarker for skin photo-stress. To evaluate the relationship between the protein carbonyl to total protein (TP) ratio (carbonylation ratio) and skin photo-stress, the authors established a methodology by which protein carbonyl can be easily and highly sensitively analysed using an optical technique based on surface plasmon resonance (SPR). To collect the stratum corneum, tape stripping was employed. Firstly, the protein carbonyl was reacted with 2,4-dinitrobenzenesulfonic acid dihydrate, and the quantity of dinitrophenylated (DNP)-protein carbonyl was determined using an anti-dinitrophenyl (anti-DNP) antibody. The mass of DNP-protein carbonyl was measured using SPR. A truncated sampling-reporting cycle of <5 min allowed speedy reporting of DNP-protein carbonyl levels. A significant difference was observed in the protein carbonyl/TP ratio (carbonylation ratio) between a sun-protected area (mid-ventral arm) and a sun-exposed area (upper cheek, P < 0.05). Additionally, the carbonylation ratio of the sun-exposed area showed a higher value than that of the sun-protected area. It was suggested that the carbonylation ratio might be a useful index of skin photo-stress.

Positively charged polymeric nanoparticles: application in improving therapeutic efficacy of meloxicam after oral administration.

The potential of positively charged polymeric nanoparticles in improving therapeutic efficacy of meloxicam (MLX), a poorly water-soluble anti-inflammatory agent was evaluated. MLX loaded positively charged nanoparticles were prepared by using poly-epsilon-caprolactone (PCL) as a biodegradable polymer and didodecyldimethylammonium bromide (DDAB) as a cationic surfactant. The MLX nanoparticles were characterized for particle size and encapsulation efficiency. MLX loaded PCL nanoparticles and MLX suspension were evaluated for their in vivo anti-inflammatory activity and ulcerogenic potential. MLX loaded PCL nanoparticles had particle sizes of approximately 300 nm and the encapsulation efficiency of MLX was approximately 90%. The polymeric nanoparticles significantly improved the anti-inflammatory activity of MLX (P< 0.01) as compared to that of MLX suspension. The higher anti-inflammatory effect was maintained for a longer duration (6 h). The polymeric nanoparticles also resulted in less ulcerogenicity as compared to that of MLX suspension.

Organic solvent-free approach to single step fabrication of Eudragit nanoparticles using Labrasol.

The present investigation describes organic volatile solvent-free approach for the single step fabrication of Eudragit nanoparticles. The solubility of various grades of Eudragit viz. Eudragit L100-55, Eudragit L100, Eudragit S100, Eudragit EPO, Eudragit RSPO and Eudragit RLPO in Labrasol (Caprylocaproyl macrogol-8 glycerides) was determined. We observed that Labrasol has the ability to solubilize various cationic Eudragits such as Eudragit RSPO, Eudragit RLPO and Eudragit EPO at a concentration as high as 200 mg/ml. We also evaluated the ability of Labrasol to act as a nanoparticle stabilizer due to its amphiphilic nature and high HLB of 14. It was observed that Eudragit EPO, Eudragit RSPO and Eudragit RLPO nanoparticles of size 110-150 nm could be easily fabricated using Labrasol as a solubilizer and nanoparticle stabilizer. Transmission electron microscopy was carried out to confirm the size and morphology of the nanoparticles. We could encapsulate hydrophobic drugs such as repaglinide and triclosan in the Eudragit RLPO nanoparticles as Labrasol also had the ability to solubilize these hydrophobic drugs. The ability of Eudragit RSPO and RLPO nanoparticles to condense plasmid DNA was also established. This is the first report that demonstrates the polymer solubilizing potential of Labrasol.

HIGHLIGHTS OF ADVANCES IN MEDICAL RETINA FROM THE VIRTUAL WORLD OPHTHALMOLOGY CONGRESS 2020.

The World Ophthalmology Congress (WOC) is one of the largest international ophthalmology conferences, taking place every two years. The event this year was the first of its kind, held as a virtual summit due to the Covid-19 pandemic. There were over 2000 talks from world experts, a virtual industry exhibition including free papers, e-posters, live symposia and presentations. Medical retina is a subspecialty in which exciting and innovative advances in research were presented. The topics covered included the use of Conbercept for Polypoidal Choroidal Vasculopathy, Faricimab in Diabetic Macular Oedema and neovascular Age Related Macular Degeneration (nAMD), Brolucizumab, Aflibercept and Port Delivery Systems in nAMD, amongst many others. Medical retina continues to be a rapidly advancing field within ophthalmology with new research findings having great implications for treatment burden and service delivery. This report summaries the highlights of advances within the medical retina subspecialty from free papers in WOC 2020.

Improving sputum collection processes to increase tuberculosis case finding among HIV-positive persons in Botswana.

SETTING: Twenty-two human immunodeficiency virus (HIV) clinics in Botswana. OBJECTIVE: To compare sputum collection rates, sputum quality and volume, and tuberculosis (TB) diagnosis rates before and after field efforts to improve sputum collection among individuals newly diagnosed with HIV with TB symptoms. DESIGN: Newly diagnosed individuals living with HIV attending 22 HIV clinics in Botswana were screened for TB from August 2012 to March 2014. Starting in May 2013, a field intervention composed of the introduction of a tracking log for presumed TB patients, and patient instructions and sputum induction to improve sputum collection rates was implemented. RESULTS: Prior to the intervention, sputum collection rates were 44.1% (384/870). Subsequently, sputum collection increased to 58.3% (579/993) (P < 0.001). Sputum quality and volume also improved. Although rates of TB diagnosis increased from 9.7% (84/870) to 12.5% (120/993), this difference was not significant (P = 0.143). CONCLUSION: Sputum collection rates among presumptive TB cases, as well as sputum quality and volume improved after implementation of the field intervention. To improve sputum collection rates, efforts at the program level should be ongoing.

Assessment of routine screening of pediatric contacts of adults with tuberculosis disease in Tanzania.

SETTING: Ten selected healthcare facilities in Tanzania, March-April 2016. OBJECTIVE: To assess the implementation of screening among pediatric contacts of adults with tuberculosis (TB) disease. DESIGN: Using a mixed-methods approach, we conducted a questionnaire study among sputum smear-positive adult TB patients and abstracted data from their patient cards to assess the implementation of a child contact management (CCM) intervention. We also conducted in-depth interviews with healthcare workers (HCWs) to solicit their views on clinical practices and challenges in CCM. RESULTS: A total of 141 adult smear-positive TB patients reported 396 children living in households; detailed information on 346 (87.4%) was available. Only 37 (10.7%) children were clinically assessed for TB, 5 (13.5%) were diagnosed with TB, and 22 started on isoniazid preventive therapy (IPT) (59.0%). Of the 320 children whose caregivers responded to whether their children had undergone human immunodeficiency virus (HIV) testing, 55 (17.2%) had been tested and one (1.8%) was HIV-positive. Forty-one HCWs described passive CCM without use of contact or IPT registers. CONCLUSION: We identified gaps in the implementation of TB screening, IPT provision, and HIV testing in pediatric contacts of adults with sputum smear-positive TB. Systematic efforts, including increasing HCW training and educating the community, may improve implementation.

Exploring the potential of N-methyl pyrrolidone as a cosurfactant in the microemulsion systems.

The effect of N-methyl pyrrolidone (NMP) on the phase behavior of two ternary systems, viz. PEG-35-castor oil (CremophoreEL)-glyceryl caprylate/caprate (Capmul MCM)-water and PEG-35-castor oil (CremophoreEL)-isopropyl myristate-water was studied. The study indicated that NMP has considerable influence on the phase behavior of both the systems. NMP increased the area of microemulsion formation in both the systems. Moreover, it also led to reduction/disappearance in the gelling region of the CremophoreEL-isopropyl myristate-water system. These observations allowed us to conclude that NMP can be considered as a cosurfactant for the development of biocompatible microemulsions.

Modular protein switches derived from antibody mimetic proteins.

Protein switches have potential applications as biosensors and selective protein therapeutics. Protein switches built by fusion of proteins with the prerequisite input and output functions are currently developed using an ad hoc process. A modular switch platform in which existing switches could be readily adapted to respond to any ligand would be advantageous. We investigated the feasibility of a modular protein switch platform based on fusions of the enzyme TEM-1 ß-lactamase (BLA) with two different antibody mimetic proteins: designed ankyrin repeat proteins (DARPins) and monobodies. We created libraries of random insertions of the gene encoding BLA into genes encoding a DARPin or a monobody designed to bind maltose-binding protein (MBP). From these libraries, we used a genetic selection system for ß-lactamase activity to identify genes that conferred MBP-dependent ampicillin resistance to Escherichia coli. Some of these selected genes encoded switch proteins whose enzymatic activity increased up to 14-fold in the presence of MBP. We next introduced mutations into the antibody mimetic domain of these switches that were known to cause binding to different ligands. To different degrees, introduction of the mutations resulted in switches with the desired specificity, illustrating the potential modularity of these platforms.

Expanding human immunodeficiency virus testing and counseling to reach tuberculosis clients' partners and families.

Recent years have shown important increases in human immunodeficiency virus (HIV) testing and counseling (HTC), diagnosis, and coverage of antiretroviral therapy (ART) among HIV-infected tuberculosis (TB) patients. Expansion of HTC for partners and families are critical next steps to increase earlier HIV diagnoses and access to ART, and to achieve international goals for reduced TB and HIV-related morbidity, mortality, transmission and costs. TB and HIV programs should develop and evaluate feasible and effective strategies to increase access to HTC among the partners and families of TB patients, and ensure that newly diagnosed people living with HIV and HIV-infected TB patients who complete anti-tuberculosis treatment are successfully linked to ongoing HIV clinical care.

Configurational encoding of complex visual forms by single neurons of monkey temporal cortex.

Single neurons in the anterior inferior temporal (IT) cortex respond to complex visual stimuli. Here we examined whether the stimulus-selectivity of the anterior IT neurons was determined solely on the basis of the geometric similarity of object forms, or was modifiable through visual experiences in adulthood. We trained Japanese monkeys (Macaca fuscata) in the visual delayed matching-to-sample task or visual stimulus-stimulus association task. Computer-generated visual forms, fractal patterns or Fourier descriptors, were used as stimuli. Single-unit recording from these trained monkeys showed that the stimulus-selectivity of neurons in the anterior IT cortex could be acquired according to the requirements of memory tasks. The results indicate that the neural representation of complex visual objects is dynamically altered through both tuning and association processes. We discuss these neurophysiological findings in relation to neuropsychological investigations of ablation effects in the primate.

Gastric aspiration for diagnosis of pulmonary tubercolosis in adult renal allograft recipients.

Of 213 renal allgraft recipients suspected to have had pulmonary tuberculosis, 132 had sputum examinations and 14 showed acid-fast bacilli. Of the remaining 118 patients, 25 had gastric aspirations, 18 had bronchoalveolar lavage, and 75 did not require further investigation because of spontaneous improvement or confirmation of an alternative diagnosis. While 9 of the 25 patients' gastric aspirate examination was positive, all the 18 who had bronchoalveolar lavage were negative for acid-fast bacilli. Eighty-one patients without expectoration had gastric aspiration directly and 14 showed acid-fast bacilli. Of the remaining 67 patients only 17 had bronchoalveolar lavage, of which three were positive for AFB and the rest did not require further testing for tuberculosis. A total of 106 patients had gastric aspiration. Acid-fast bacillus positivity was significantly more (P<.01) in patients with abnormal chest radiographs as compared with patients with normal chest radiographs as compared with patients with normal chest radiograph results. We suggest gastric aspiration for AFB in all renal transplant recipients who have fever, scanty expectoration, and abnormal chest radiograph with clinical suspicion of pulmonary tuberculosis.

The effect on patient management of temporary non-availability of immunofluorescence for renal biopsy reporting.

Delay in reporting the immunofluorescence findings on renal biopsies, owing to an interruption in supply of reagents, made possible a retrospective analysis of the effect of the lack of this information on patient management. Hospital case records of the 39 patients so affected were reviewed to determine what changes in their management took place after the immunofluorescence findings became available. The clinical, laboratory, and light microscopic findings in all except a case of pauci-immune crescentic glomerulonephritis allowed management decisions to be made that were not influenced by immunofluorescence findings. This was owing to correct prediction of the immunofluorescence findings, as in cases of IgA nephropathy presenting with recurrent haematuria; the adequacy of light microscopy in the interpretation of graft biopsies, in classifying lupus nephritis and in most cases of nephrotic syndrome; and the absence of entities identifiable only by immunofluorescence among these patients.

Interobserver variation in the reporting of cervical colposcopic biopsy specimens: comparison of grading systems.

AIMS: To assess interobserver variation in reporting cervical colposcopic biopsy specimens and to determine whether a modified Bethesda grading system results in better interobserver agreement than the traditional cervical intraepithelial neoplasia (CIN) grading system. METHODS: One hundred and twenty five consecutive cervical colposcopic biopsy specimens were assessed independently by six histopathologists. Specimens were classified using the traditional CIN grading system as normal, koilocytosis, CIN I, CIN II, or CIN III. The specimens were also classified using a modified Bethesda grading system as either normal, low grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL). Participants were also asked to categorise biopsy specimens by the CIN system with the addition of the recently proposed category "basal abnormalities of uncertain significance (BAUS)". The degree of agreement between participants was assessed by kappa statistics. RESULTS: Using the CIN system, interobserver agreement was generally poor: unweighted and weighted kappa values between individual pairs of observers ranging from 0.05 to 0.34 (average 0.20) and from 0.20 to 0.54 (average 0.36), respectively. With the modified Bethesda system, interobserver agreement was better but still poor: unweighted and weighted kappa values ranging from 0.15 to 0.58 (average 0.30) and from 0.21 to 0.61 (average 0.36), respectively. There was little or no agreement between observers in the diagnosis of BAUS. CONCLUSIONS: Interobserver agreement in the reporting of cervical colposcopic biopsy specimens using the CIN grading system is poor. Agreement, while still poor, is better when a modified Bethesda grading system is used. There is little or no consensus in the diagnosis of BAUS.

Renal cortical necrosis following exposure to sap of the marking-nut tree (Semecarpus anacardium).

An 18-year-old man developed skin lesions and anuria following exposure to sap of the marking-nut tree (Semecarpus anacardium). Renal biopsy showed diffuse cortical necrosis. The mechanism of nephrotoxicity of the sap is unknown but may be due to its phenolic constituents.

Eosinophilic leukocytes in diffuse proliferative and exudative glomerulonephritis.

Differential counts of glomerular eosinophils and neutrophils were performed on renal biopsies from 16 patients with diffuse proliferative and exudative glomerulonephritis. The results indicate that eosinophils and neutrophils are present in the glomerular exudate in the same proportion as in the peripheral blood. The eosinophilia present in some of the cases could not be etiologically related to the acute nephritis and probably represented a chance association, showing how a well known histological entity can sometimes be modified in a tropical environment. The functional effects, if any, of this modification require further study.

Glomerular pathology in leprosy. An electron microscopic study.

Electron microscopic examination of renal biopsies from 19 patients with leprosy who had edema, proteinuria, or hematuria showed a proliferative glomerulonephritis in 12, amyloidosis in 2, and no lesion in 5. The proliferative glomerulonephritis was of different patterns: diffuse with or without exudation, focal, or mesangial. Subendothelial and/or subepithelial deposits were seen in five biopsies. Of the patients with glomerulonephritis, 3 had a reduced total serum complement level, 5 had erythema nodosum leprosum, 5 had evidence of recent streptococcal infection, and 2 had microfilariae in the peripheral blood. The significance of these findings is discussed.

Renal failure following snake bite. A clinicopathological study of nineteen patients.

Clinical, hematological, and renal biopsy findings in 19 unselected patients with renal failure following snake bite, including eight bitten by Russell's viper, are presented. Hematological findings were variable and did not influence treatment. Renal histology was a good guide to prognosis; patients with normal histology recovered with conservative management, those with tubular necrosis responded well to dialysis, while those with cortical necrosis responded only partially. Peritoneal dialysis was found to be an adequate form of treatment in the majority of patients.

How useful is immunofluorescence in tropical renal pathology?

A study of 841 renal biopsies from a south Indian hospital showed that immunofluorescence significantly helped in making a diagnosis in 74 cases. This contribution was most useful in biopsies from patients with nephritic or haematuric presentations; in those whose biopsies showed mesangial proliferative, focal proliferative, or crescentic glomerulonephritis; and in biopsies without changes detectable by light microscopy from patients with systemic lupus erythematosus.