Comparative evaluation of aqueous and plasma concentration of topical moxifloxacin alone and with flurbiprofen in patients of cataract surgery

Objectives:

To determine the aqueous and plasma concentrations of moxifloxacin administered topically alone and with flurbiprofen in patients undergoing cataract surgery.

Materials and Methods:

A total of 50 subjects scheduled for routine cataract surgery were randomly allocated to two groups (n = 25 each). Group-1 patients were treated with topical moxifloxacin alone: One drop 6 times/day for 3 days before surgery and one drop 4 times on the day of surgery: Group-2 patients were treated with topical moxifloxacin as in Group-1 and with topical flurbiprofen: One drop 4 times/day for 3 days before and on the day of surgery. The interval between two drugs was 30 min for last 3 days and 15 min on the day of surgery. Last dose was administered 1 h before aqueous humor and blood sampling for both the groups. The antibiotic concentration in aqueous humor and plasma were determined by using high performance liquid chromatography.

Results:

The mean concentration of moxifloxacin in aqueous humor was 1.71 ± 0.82 mg/ml in Group-1 and 2.39 ± 1.34 mg/ml in Group-2. Concentrations of moxifloxacin in aqueous humor were significantly higher in Group-2 than that of Group-1.

Conclusion:

Flurbiprofen may increase the concentration of moxifloxacin in aqueous humor.KEY WORDS: Aqueous humor, cataract surgery, flurbiprofen, moxifloxacin     

Exploring structural requirements of aurone derivatives as antimalarials by validated DFT-based QSAR, HQSAR, and COMFA–COMSIA approach

Chloroquine resistance is nowadays a great problem in malaria. Aurone derivatives were effective against chloroquine resistant parasite. Validated density functional theory (DFT)-based chemometric modeling, hologram QSAR (HQSAR), comparative molecular field analysis (CoMFA), and comparative molecular similarity analysis (CoMSIA) studies were conducted on 35 aurone derivatives having antimalarial activity. 2D-QSAR models were developed on the training sets by Y-based ranking method. This model was validated on 50 pairs of the test and the training sets by k-Means cluster analysis method. HQSAR, CoMFA, and CoMSIA models were validated by standard techniques and each method validates the DFT-based 2D-QSAR study and in turn validates the earlier observed structural activity relationship data as well as each other. DFT-based 2D-QSAR model suggests that the increase of Mulliken charge at C₁₄ and HOMO density located on C₁₁ may be conducive to antimalarial activity. Ethyl group attached to C₁₄ and the increase of the value of chemical potential may be beneficial for antimalarial activity. Methoxy fragment is important for better antimalarial activity by HQSAR study. CoMFA analysis shows a favorable steric green region is located near C₁₄ whereas the unfavorable yellow region is far away from C₁₄. A large blue region located near C₁₄ indicates the positively charged groups are favorable at this position. CoMSIA steric features correlates well with the CoMFA steric features. CoMSIA study suggests the bulky hydrophobic substitution at C₁₄ is necessary for antimalarial activity. These results may be utilized to obtain potential antimalarial molecules.     

Psychological predictors of SMR-BCI performance

Background

After about 30 years of research on Brain-Computer Interfaces (BCIs) there is little knowledge about the phenomenon, that some people - healthy as well as individuals with disease - are not able to learn BCI-control. To elucidate this “BCI-inefficiency” phenomenon, the current study investigated whether psychological parameters, such as attention span, personality or motivation, could predict performance in a single session with a BCI controlled by modulation of sensorimotor rhythms (SMR) with motor imagery.

Methods

A total of N = 83 healthy BCI novices took part in the session. Psychological parameters were measured with an electronic test-battery including clinical, personality and performance tests. Predictors were determined by binary logistic regression analyses.

Results

The output variable of the Two-Hand Coordination Test (2HAND) “overall mean error duration” which is a measure for the accuracy of fine motor skills accounted for 11% of the variance in BCI-inefficiency. The Attitudes Towards Work (AHA) test variable “performance level” which can be interpreted as a degree of concentration and a neurophysiological SMR predictor were also identified as significant predictors of SMR BCI performance.

Conclusion

Psychological parameters as measured in this study play a moderate role for one-session performance in a BCI controlled by modulation of SMR.     

A new (semantic) reflexive brain-computer interface: in search for a suitable classifier

The goal of the current study is to find a suitable classifier for electroencephalogram (EEG) data derived from a new learning paradigm which aims at communication in paralysis. A reflexive semantic classical (Pavlovian) conditioning paradigm is explored as an alternative to the operant learning paradigms, currently used in most brain-computer interfaces (BCIs). Comparable with a lie-detection experiment, subjects are presented with true and false statements. The EEG activity following true and false statements was classified with the aim to separate covert ‘yes’ from covert ‘no’ responses.Four classification algorithms are compared for classifying off-line data collected from a group of 14 healthy participants: (i) stepwise linear discriminant analysis (SWLDA), (ii) shrinkage linear discriminant analysis (SLDA), (iii) linear support vector machine (LIN-SVM) and (iv) radial basis function kernel support vector machine (RBF-SVM).The results indicate that all classifiers perform at chance level when separating conditioned ‘yes’ from conditioned ‘no’ responses. However, single conditioned reactions could be successfully classified on a single-trial basis (single conditioned reaction against a baseline interval). All of the four investigated classification methods achieve comparable performance, however results with RBF-SVM show the highest single-trial classification accuracy of 68.8%. The results suggest that the proposed paradigm may allow affirmative and negative (disapproving negative) communication in a BCI experiment.     

Right ventricular outflow tract obstruction caused by a right coronary cusp prolapse: An unusual finding

Patients with large sub-pulmonic ventricular septal defect (VSD) present early as a results of their complications. Some present late, due to the restriction of VSD by the right coronary cusp (RCC) due to its prolapse. In this report, we present a rare case of sub-pulmonic VSD in a 33-year-old man who developed a sub-pulmonic stenosis due to the prolapse of the RCC into the right ventricular outflow tract.     

Primary lymphoepthelial carcinoma of the parotid gland,pictorial review of a rare entity

Lymphoepithelial carcinoma (LEC) is a rare malignancy of the salivary gland arising from the parotid in 80% of cases. LEC is indistinguishable histologically from more common non‐keratinising undifferentiated nasopharyngeal carcinoma (NPC). Up to 40% of patients with primary LEC present with a cervical metastasis and histological assessment of the primary lesion or nodal metastasis may be reported as NPC. The absence of a nasopharyngeal lesion on imaging and endoscopic assessment together with a parotid mass strengthens the case for a LEC. A retrospective review of three cases of primary parotid LEC presenting to a tertiary head and neck clinic was performed. Clinical information, imaging and histopathology findings are presented in the form of a pictorial review. Two female and one male patient with an average age of 42 years presented with a neck lump. Initial pathology results were poorly differentiated carcinoma (2/3) and possible NPC (1/3). MR neck revealed unilateral parotid masses with ipsilateral cervical lymphadenopathy and assessment of the nasopharynx was negative (3/3). Resection occurred in all patients and consensus was metastatic LEC with parotid primary in all cases (3/3). 2 patients are disease free, and 1 patient is deceased (as a result of disease) at the time of this report. Lymphoepithelial carcinoma is identical histologically to NPC, this pictorial review highlights the need for clinical and radiological correlation to establish the diagnosis.     

Tissue-specific expansion of NKT and CD5+B cells at the onset of autoimmune disease in (NZBxNZW)F1 mice

Natural killer T (NKT) cells and CD5(+)B cells were searched for in various immune organs of autoimmune prone (NZBxNZW)F(1) (NZB/W F(1)) mice. The number of lymphocytes increased in the liver, spleen, and peritoneal cavity after the onset of disease (at the age of 30 weeks) while the number of thymocytes decreased at that time. Prominent changes of lymphocyte subsets were seen in the liver and peritoneal cavity, namely, expansion of IL-2Rbeta(+)TCRalpha beta(int) cells in the liver and of CD5(+)B220(+) cells in the peritoneal cavity. The majority of TCRalpha beta(int) cells in the liver were NK1.1(+), and CD5(+)B cells in the peritoneal cavity were CD1d(+). Proteinuria became prominent in NZB/W F(1) mice with the progression of disease. In parallel with this progression, the proportion of NKT cells decreased slightly in the liver, but their absolute number remained at a high level in this organ. These NKT cells were CD4(+) and used an invariant chain of Valpha14Jalpha281 for TCRalpha. Reflecting the elevation of CD5(+)B cells, autoantibodies against hepatocyte cytoplasmand denatured DNA were detected in sera. Although NKT cells are known to be immunoregulatory cells in some autoimmune mice, the present results raise the possibility that NKT cells as well as CD5(+)B cells might be associated with the onset of autoimmune diseases in NZB/W F(1) mice. Indeed, NKT cells in F(1) mice had a high potential to induce autoimmune-like inflammationwhen alpha-galactosylceramide was administered or when active NKT cells were transferred into young F(1) mice.     

Binding interactions and FRET between bovine serum albumin and various phenothiazine-/anthracene-based dyes: a structure–property relationship

The present study demonstrates binding interactions and Förster resonance energy transfer (FRET) between bovine serum albumin (BSA) and a series of structurally and electronically diverse phenothiazine (PTZ) and anthracene (ANT) dyes. Upon selective excitation of tryptophan (Trp) residues of BSA, radiationless energy transfer to a dye takes place, resulting in fluorescence quenching of the former. Fluorescence quenching mechanisms, FRET parameters, possible locations, and binding constants of dyes with the BSA have been examined to deduce a structure–property relationship. The mechanism of quenching is apparently static in nature. PTZ dyes with heteroatoms and a pentyl tail (C5-PTZ) attached to them were found to have a stronger binding affinity with BSA as compared to ANT dyes. Stronger binding affinities of C5-PTZ dyes with BSA result in greater energy transfer efficiencies (E_T). A dye with a strong electron-withdrawing group present in it has shown better energy accepting capability. A FRET study with dicyanoaniline (DCA) analogs of PTZ and ANT dyes (C5-PTZDCA and ANTDCA, respectively) revealed that E_T depends on electronic and structural factors of molecules. An almost orthogonal geometry between ANT and DCA moieties (∼79°) in ANTDCA induces the greater extent of electron transfer from ANT to DCA, showing a higher E_T for this dye as compared to C5-PTZDCA in which the torsion angle is only ∼38°. Further, the observed facts have been validated by experimentally determined bandgaps (using cyclic voltammetry experiments) for all the dyes. Thus, the hydrophobic character and the presence of interactive substituents along with the electron-accepting abilities majorly control the FRET for such dyes with BSA.

The present study demonstrates binding interactions and Förster resonance energy transfer (FRET) between bovine serum albumin (BSA) and a series of structurally and electronically diverse phenothiazine (PTZ) and anthracene (ANT) dyes.