Role of Histomorphology and Chronic Inflammation Score in Chronic Dacryocystitis.

INTRODUCTION: Diseases of lacrimal drainage system account for nearly 3% of visits to eye clinic. Chronic dacryocystitis is a frequently encountered disorder among these patients. Histomorphology of specimens obtained after Dacryocystorhinostomy (DCR) is a pertinent indicator of prognostic outcome. AIM: The aim of the study was to evaluate histopathology of specimens obtained after DCR and to elucidate patterns and score of chronic inflammation encountered. MATERIALS AND METHODS: The study was conducted for a period of one year. Total of 50 patients who were clinically diagnosed as Chronic Dacryocystitis and underwent DCR were included. Following DCR, specimens of lacrimal sac, nasal mucous membrane and nasal bone were collected. Histopathological slides were examined for chronic inflammatory cell infiltration, fibrosis and capillary proliferation and were graded according to severity, in each specimen. A Chronic Inflammation Score (CIS) was recorded for each case. RESULTS: The average age of patients was 39.04±14.22 years and their age ranged between 13 and 62 years. There were 28 (56%) females and 22 (44%) males in the study group. The nasal bone did not reveal any abnormality in any case. The nasal mucous membrane showed mild chronic inflammatory cell infiltration in 46 (92%) cases and moderate degree in 4 (8%) patients. Chronic inflammation with granulation tissue formation was noted in lacrimal sacs of all patients. The CIS revealed that 14 (28%) cases belonged to "mild" group, 26 (52%) to "moderate" group and 10 (20%) to "severe" category. CONCLUSION: The inclusion of CIS in histomorphological evaluation of DCR specimens is recommended since it is one of the parameters that influence course of the disease.

Internal charge transfer based ratiometric interaction of anionic surfactant with calf thymus DNA bound cationic surfactant: Study I.

Cetyl trimethyl ammonium bromide (CTAB) binds calf thymus (ct-) DNA like anionic biopolymers electrostatically and established equilibrium both in the ground as well as in excited state in aqueous medium at pH 7. Anionic sodium dodecyl sulfate (SDS) does not show even hydrophobic interaction with ct-DNA at low concentration. On contrary, SDS can establish well defined equilibrium with DNA bound CTAB in ground state where the same CTAB-DNA isosbestic point reappears. First report of internal charge transfer (ICT) based binding of CTAB with ct-DNA as well as ICT based interaction of anionic SDS with DNA bound CTAB that shows dynamic quenching contribution also. The reappearance of anodic peak and slight increase in cathodic peak current with increasing concentration (at lower range) of anionic SDS, possibly reflect the release of CTAB from DNA bound CTAB by SDS.

Quinone-Bodipy H-bonding interaction over π-stacking in toluene.

Quinone type compounds (o-chloranil, p-chloranil and DDQ) demonstrate excellent H-bonding interactions with a meso-phenol Bodipy dye (1) in both ground and excited state in a non-polar toluene medium. The spectroscopic detection of isosbestic absorption occurs with both quinones and fullerenes, but only quinones form isoemissive complexes with dye 1. (1)H NMR study and Monte Carlo global minima searching justified the above mentioned results with efficiency.

Charge transfer energies of the complexes of (dibenzoylmethanato)boron difluoride with indeno-pyridines and polynuclear aromatic hydrocarbons.

Charge transfer complexes of electron deficient (dibenzoylmethanato)boron difluoride (DBMBF2) with polyaromatic hydrocarbons (A), as well as with highly electron rich indeno-pyridines (I) compounds in ethanol medium have been studied by electronic absorption spectroscopy. Absorption band due to a charge-transfer (CT) transitions are observed in the visible region. Utilizing the CT transition energy, the vertical electron affinities (EA(v)) of DBMBF2 in ethanol has been calculated. The value of EA(v) for DBMBF2 is found to be 2.28 eV, this is the first report of its electron affinity value. We have calculated the degrees of CT and transition dipole strengths of the DBMBF2/A and DBMBF2/I complexes. Along with both theoretically calculated and experimentally obtained vertical ionization potentials of the indeno-pyridine donors have been estimated for the first time. I show high degree of charge transfer along with high ground state stability similar to that of A. Thus indeno-pyridine (I) donors are also as good as aromatic hydrocarbons (A) for DBMBF2, having equivalent ionization potential like that of aromatic hydrocarbons.

Types of interaction of meso-tetraphenylporphyrin with alkali and alkaline-earth metal ions.

The cavity in a porphyrin can accommodate metal ions through electron donor-acceptor (EDA) interaction in acetonitrile media without any specially designed fabrication with the porphyrin subunit. Alkali metal ion forms a complex with meso-tetraphenylporphyrin (TP) in 2:1 stoichiometry, while the bivalent Mg(2+) ion follows a 1:1 stoichiometry. A fluorescence interaction study indicated that TP can behave like a chemosensor for these ions present in the blood electrolytes. Specifically, for the alkali metal ions intensity-based sensing was observed, due to inhibition of photoinduced electron transfer (PET), entailing enhancement of fluorescence intensity, and for the alkaline-earth Mg(2+) a mixed quenching was observed. Na(+) and K(+) ions can be differentiated depending upon the extent of fluorescence enhancement.

Zinc ion-tetraphenylporphyrin interactions in the ground and excited states.

In the present article, tetraphenylporphyrin a new ratiometric fluorescence sensitizer for zinc ion has been proposed. Electronic absorption, emission and (1)H NMR spectral characteristics of meso-tetraphenylporphyrin (TPP) have been studied in acetonitrile medium in the presence of zinc perchlorate. Absorption spectral studies indicate the formation of a new complex between zinc ion and the porphyrin moiety in the ground state as distinguished from the characteristics of metalo(zinc) porphyrin compound. The energy of maximum fluorescence of porphyrin shifts towards blue with the addition of Zn(ClO(4))(2). Steady state emission studies point to the existence of two emitting species viz, the solvated and the complexed porphyrin in equilibrium. The fluorescence emission of tetraphenylporphyrin at 651-nm bands decreases while that at 605 nm increases upon zinc ion interaction in acetonitrile. Thus, the TPP can behave as a ratiometric fluorescent sensor. This fluorescence modulation of TPP should be applicable to dual-wavelength measurement of various biomolecules or enzyme activities. (1)H NMR spectra of the porphyrin suffered a radical change with the addition of zinc perchlorate which points to the formation of a new porphyrin complex. This change is due to the difference in the electron-donating ability of the pyrrolic nitrogens before and after complexation with Zn(2+). The values of equilibrium constant for the binding process have been determined in acetone and acetonitrile, in both ground and excited states.

Environmental effects on luminescence of meso-tetra-2-chlorophenylporphyrin.

Effects of solvent polarity on the photophysical behaviour of meso-tetra-2-chlorophenylporphyrin have been studied by means of steady-state absorption and fluorescence, as well as time-resolved fluorescence techniques. A non-mirror symmetric absorption and emission spectra due to vibronic borrowing were obtained. Time-resolved fluorescence study indicated the bi-exponential decay kinetics for both the emission bands, observed in steady-state emission spectra. Such findings implied that there exists two emitting species on the photoinduced conformational excursions of the excited-state equilibrium and also that their relative contributions to emission change with solvent polarity. Monte Carlo conformational search based on force-field molecular mechanics was performed to locate equilibrium conformers in the ground state which enable evaluation of the ground-state barrier energies. This was followed by CIS and ZINDO calculations to explore the excited-state barriers.

Photophysical properties of the 8-phenyl analogue of PM567: a theoretical rationalization.

The absorption and emission spectroscopic investigations of the C-8-phenyl substituted analogue of the pyrromethene dye PM567 in various polar, non-polar as well as protic and aprotic solvents are reported. The solvatochromic shifts of the spectral bands were studied in a multitude of polar, non-polar and protic, aprotic solvents followed by a multilinear regression in which several solvent parameters were simultaneously analysed. Comparison of the experimental results with those obtained by gas phase ab initio computation with CIS, TD-HF and TD-DFT theories using 6-31G* basis set reveal an overestimation of the experimentally measured excitation parameters by all these theoretical models. However, the trends in the experimental results agree with those calculated theoretically.

Laboratory-based Japanese encephalitis surveillance in Nepal and the implications for a national immunization strategy.

We report on two years of Japanese encephalitis (JE) surveillance in Nepal and the implications for a national immunization strategy. From May 2004 to April 2006, 4,652 patients with encephalitis were evaluated. A serum or cerebrospinal fluid specimen was collected from 3198 (69%) patients of which 1,035 (32%) were positive by Japanese encephalitis IgM ELISA. Most cases (N = 951, 92%) were from the 24 Terai districts (i.e., southern plains, 12.3 million persons) with the majority (N = 616, 65%) from four western Terai districts (population = 1.8 million). The case fatality ratio was 14.7% and 6.3% and the proportion of cases under 15 years old was 52% and 62% in the four western and 20 non-western Terai districts, respectively. Japanese encephalitis immunization targeting residents one year of age and older in the western districts and one through 14 years old in the non-western Terai districts may have reduced Japanese encephalitis cases by 84% and deaths by 92%, nationally.

Design and development of a new pyrromethene dye with improved photostability and lasing efficiency: theoretical rationalization of photophysical and photochemical properties.

In an attempt to develop a photostable and efficient pyrromethene compound for use in liquid dye lasers, three congeners of the commercially available pyrromethene 567 (PM567) laser dye were synthesized and their photophysical properties, lasing efficiencies, and photochemical stabilities were studied. In general the presence of an aryl group at C-8 of the pyrromethene chromophore increased the photostability. One of the congeners possessing a C-8 trimethoxyphenyl moiety showed significantly improved lasing parameters than PM567. Compared to PM567, the photochemical stability of the new dye was 2-fold, while it showed an equivalent lasing efficiency to that of PM567 at a significantly lower concentration. The increased photostability of these new dye molecules could be explained by theoretical calculation on their capacity to generate singlet oxygen ((1)O(2)) and probability of reaction with (1)O(2). Our calculations were in agreement with the experimental results and indicated that a systematic design of new derivatives of pyrromethene chromophore might lead to improved laser dye molecules.

Photophysical investigations on non-covalently linked fullerene/tetraarylporphyrin supramolecular complexes.

The host-guest interactions of various tetraarylporphyrins (TP), viz., 5,10,15,20-tetraphenyl-21H,23H-porphyrin (1), 5,10,15,20-tetrakis(octadecyloxyphenyl)-21H,23H-porphyrin (2) and 5,10,15,20-tetrakis(dodecyloxyphenyl)-21H,23H-porphyrin (3) with C60 and C70 have been studied by 1H NMR, UV-vis and fluorescence spectroscopic techniques in toluene medium. All the fullerene/porphyrin complexes are found to be stable with 1:1 stoichiometry. Binding constants (K) of all the fullerene/porphyrin complexes have been determined by fluorescence quenching experiment. The trend in K values revealed that the presence of long chain n-alkyl group in tetraarylporphyrin effectively and remarkably increases the selectivity ratio of C70 over C60. Theoretical calculations have extended a good support in interpreting the stability difference between various fullerene/TP complexes.

Spectrophotometric study of the supramolecular complexes of [60]- and [70]Fullerenes with biscalix[6]arene and crown[4]calix[6]arene.

[60]- and [70]Fullerenes have been shown to form 1:1 supramolecular complexes with bis[2-(5,11,17,23,29,35-hexa-tert-butyl-37,38,39,40,41-pentahydroxycalix[6]arenyl-oxy ethyl ether) (1) and 5,11,17,23,29,35-hexa-tert-butyl-37,38,40,41-tetra hydroxyl-39,42-(crown-4)calix[6]arene (2) in CHCl3 medium by electronic absorption spectroscopy. Formation constants (K) of the complexes of [60]- and [70]fullerenes with 1 and 2 have been determined at room temperature from which free energy of formation values of the complexes have been estimated. The very high formation constant value of [60]fullerene/1 complex (5900 dm3 mol-1) in indicative of formation of inclusion complex. Moreover, PM3 calculations reveal that intermolecular interaction between [60]fullerene and 1 proceeds through quite deep energy molecular orbital.

Inclusion properties of 3-fluoromesotetraphenylporphyrin with C60 and C70.

To improve the selectivity ratio of C70 over C60, a new designer molecule, viz., 3-fluoromesotetraphenylporphyrin (1) has been reported in the present investigations. Fluorescence studies reveal that the Q-absorption band of 1 gets sufficient quenching effect upon addition of both C60 and C70. Binding constants (K) of the C60/1 and C70/1 complexes are estimated to be 580 and 10,800 dm3 mol(-1), respectively. Thus, K(C70)/K(C60) is approximately 19 which is very large and even comparable with other macrocyclic host molecules like calix[5]arene, azacalix[m]arene[n]pyridine, cyclotriveratrylenophane and calixarene bisporphyrin. 1H NMR chemical shift measurements show that the -NH- proton of 1 suffers more shifts in presence of C70 compared to C60. This finding also offers a good support in favor of high K value for C70/1 complex as well as large selectivity ratio of C70 over C60.

NMR spectrometric studies of complexation of [60]fullerene with series of meso-tetraphenylporphyrins.

Extensive 1H NMR spectrometric studies have been done to gain information on the nature of molecular interactions of the supramolecular complexes of [60]fullerene with a series of meso-tetraphenylporphyrins, namely, meso-5,10,15,20-tetraphenylporphyrin (1), meso-5,10,15,20-tetra-2-bromophenyl-porphyrin (2) and meso-5,10,15,20-tetra-2-chlorophenyl-porphyrin (3) in toluene medium. [60]Fullerene has been shown to form 1:1 adducts with the above series of meso-tetraphenylporphyrins. Formation constants (K) for all the complexes have been determined from the systematic variation of the NMR chemical shifts of beta proton of the porphyrin in presence of [60]fullerene. It has been observed that 3 acts as a better donor in forming supramolecular complex with [60]fullerene.

Endemic Japanese encephalitis in the Kathmandu valley, Nepal.

Japanese encephalitis (JE) is endemic in the Terai region of Nepal. There is little information on the occurrence of JE outside the Terai and particularly in the densely populated Kathmandu valley. Acute encephalitis syndrome (AES) cases were detected using a sentinel surveillance system that has been functioning since 2004. JE was confirmed using anti-JE IgM ELISA. All laboratory-confirmed JE cases that occurred in the Kathmandu valley during 2006 were followed up for verification of residence and travel history. JE was confirmed in 40 residents of the Kathmandu valley, including 30 cases that had no history of travel outside the valley during the incubation period. Incidence was 2.1/100,000 and the case fatality was 20% (8/40). Currently, JE prevention is focused on the Terai region in Nepal; given the evidence, this should be reviewed for the possible inclusion of the Kathmandu valley in the national JE prevention and control program.

Spectrophotometric studies of complexation of [60]fullerene with series of aromatic hydrocarbon molecules containing flexible phenyl substituents.

The absorption spectra of the electron donor-acceptor complexes of [60]fullerene with five different aromatic hydrocarbon (AH) molecules containing flexible phenyl substituents have been investigated in toluene medium. An absorption band due to charge transfer (CT) transition is observed in each case in the visible region. The experimental CT transition energies are well correlated with the vertical ionization potentials of the AHs studied (through Mulliken's equation) from which we extract degrees of charge transfer, oscillator and transition dipole strengths of the CT complexes. The degrees of CT in the ground state of the complexes have been found to be very low (0.49-0.55%). The formation constants (K) for the complexes of [60]fullerene with the aromatic hydrocarbons have been determined by UV-vis spectroscopy. Both K values and PM3 calculations on [60]fullerene/AH complexes reveal that nature of substitution in the donor moiety as well as steric compatibility with the acceptor molecule govern the process of EDA complex formation.

Study of electron donor-acceptor complexes of tri-n-octyl amine with [60]- and [70]fullerenes and some other electron acceptors by absorption spectrophotometric method.

Electron donor-acceptor (EDA) complexes of tri-n-octylamine (TOA) with [60]- and [70]fullerenes and some other electron acceptors have been studied in chloroform medium by absorption spectrophotometric technique. Charge transfer (CT) absorption bands are observed in the visible region. Vertical ionization potential of TOA was determined utilizing CT transition energy. Oscillator strengths, transition dipole strengths and resonance energies for all the complexes have been calculated. [60]Fullerene/TOA and [70]fullerene/TOA complexes are found to decay slowly with time. Kinetics of these reactions have been studied and activation energies for such processes have been estimated. Ab initio calculations suggest that complexation of [70]fullerene with TOA is enthalpy favoured.

Absorption spectrophotometric study of supramolecular complexation of [60]- and [70]fullerenes with 24,26-dimethoxy-25,27-dihydroxy calix[4]arene.

Supramolecular interactions of 24,26-dimethoxy-25,27-dihydroxy calix[4]arene (1) with [60]- and [70]fullerenes have been studied in only chloroform and in a ternary solvent mixture comprising of chloroform, ethyl alcohol and toluene by UV-vis absorption spectrophotometric method. The experimental results are explained using the model that takes into account the interaction between electronic subsystems of 1 and fullerene. The most interesting feature is the preference of [60]fullerene over [70]fullerene for 1 in ternary solvent mixture as revealed by higher value of formation constant of [60]fullerene/1 complex. The selectivity towards [60]fullerene opens up the way toward self-assembling systems and new separation and purification methods for fullerenes.

Energies of charge transfer and formation equilibria of the complexes of [70]fullerene with some interesting polyaromatic molecules.

We have investigated electron donor-acceptor complexes of [70]fullerene with various polyaromatic molecules (PAM) with different vertical ionization potentials (I(D)(v)). Well defined charge transfer (CT) absorption bands have been located in the visible region. We extract degrees of charge transfer, oscillator and transition dipole strengths by analyzing the transition energy of the CT band as a function of I(D)(v) of the donors studied. The experimental results were explained using a theoretical model that takes into account the interaction between electronic subsystems of PAM with [70]fullerene. Trends in the formation constant for the [70]fullerene/PAM complexes were discussed in terms of enthalpies and entropies of formation.

Ocular involvement in diabetes mellitus.

Diabetes is a worldwide medical problem and is a significant cause of morbidity and mortality. It has considerable impact on both the patient and the society because it typically affects individuals in their most productive years. It is also one of the leading causes of blindness and visual impairment. A person with diabetes has 25 times the risk of blindness compared to a non-diabetic. This article reviews the variety of ways in which the eye and its adnexa can be involved in diabetes mellitus.