Outcomes of accelerated collagen cross linking in progressive paediatric keratoconus

Purpose

To determine the efficacy and safety of pediatric accelerated cross linking (CXL).

Methods

A prospective study on progressive keratoconus (KC) cases under ≤18 years of age. Sixty four eyes of thirty nine cases underwent epithelium-off accelerated CXL protocol. Visual acuity (VA), slit-lamp examination, refraction, pentacam reading of keratometry (K), corneal thickness, and thinnest location pachymetry were noted. Cases were followed up on days 1, 5, and at 1^st, 3^rd, 6^th, and 12th-month post procedure.

Results

Statistically, significant improvement of the mean aided VA, K, and mean corneal astigmatism (p < 0.0001) was noted. Mean Kmax reading reduced from 55.5 ± 5.64 (47.4-70.4) diopter (D) preoperatively to 54.41 ± 5.51 (46-68.3) D at 12 months postaccelerated CXL. Two cases had progression. Complications encountered were sterile infiltrate and persistent haze.

Conclusion

Accelerated CXL is effective and efficacious in pediatric KC.

CO2 utilization as a soft oxidant for the synthesis of styrene from ethylbenzene over Co3O4 supported on magnesium aluminate spinel: role of spinel activation temperature

Magnesium aluminate spinel (MgAl2O4) supported Co3O4 catalysts are synthesized and tested for the oxidative dehydrogenation (ODH) of ethylbenzene using CO2 as a soft oxidant. The effect of spinel calcination temperature on the catalytic performance has been systematically investigated. With an increase in the activation temperature from 600 to 900 °C, the active presence of a single-phase MgAl2O4 spinel is observed. A catalyst series consisting of MgAl2O4 spinel with varying Co loadings (10-20 wt%) were prepared and systematically distinguished by ICP, XRD, BET, TPR, NH3-TPD, UV-Vis DRS, FT-IR, XPS, SEM, and TEM. Among the tested cobalt catalysts, 15Co/800MA sample derived by calcination of MgAl2O4 support at 800 °C exhibits the most excellent catalytic performance with the maximum ethylbenzene conversion (≥ 82%). Also, high yields of styrene (≥ 81%) could be consistently achieved on the same active catalyst. Further, the catalyst exhibited almost stable activity during 20 h time-on-stream with a slow decrease in the ethylbenzene conversion from 82 to 59%. However, the selectivity of styrene (98%) stayed almost constant during the reaction. Activation of the MgAl2O4 spinel at 800 °C facilitates a dramatic chemical homogeneity for the alignment of Co3O4 nanoparticles on the surface of the active catalyst. Moreover, the isolated Co3O4 clusters have a strong chemical/electronic interaction with the Mg2+ and Al3+ ions on the support perform a crucial role to achieve the maximum catalytic activity.

Design, synthesis, in silico and in vitro evaluation of thiophene derivatives: A potent tyrosine phosphatase 1B inhibitor and anticancer activity

A series of novel methyl 4-(4-amidoaryl)-3-methoxythiophene-2-carboxylate derivatives were designed against the active site of protein tyrosine phosphatise 1B (PTP1B) enzyme using MOE.2008.10. These molecules are also subjected for in silico toxicity prediction studies and considering their corresponding drug scores, it implied that, the molecules are promising as anticancer agents. The designed compounds were synthesized by using suitable methods and characterized. They were subjected to inhibitory activity against PTP1B and in vitro anticancer activity by MTT assay. Most of the tested compounds showed potent inhibitory activity against PTP1B, among the compounds tested, compound 5b exhibited the highest activity (IC₅₀=5.25µM) and remarkable cytotoxic activity at 0.09µM of IC₅₀ against the MCF-7 cell line. In addition to this, compound 5c also showed potential anticancer activity at 2.22µM of IC₅₀ against MCF-7 and 0.72µM against HepG2 cell lines as well as PTP1B inhibitory activity at IC₅₀ of 6.37µM.

Palatal changes of reverse smokers in a rural coastal Andhra population with review of literature

AIM

To investigate and record the palatal changes in individuals habituated to reverse chutta smoking in rural coastal Andhra population.

MATERIALS AND METHODS

Sixty individuals out of whom 47 females and 13 males habituated to reverse smoking with no other tobacco and alcohol habits and no other systemic disturbances were selected. The palatal changes were recorded by six examiners. Database were searched for the following terms "reverse smokers," "nicotina palatini" and "palatal lesions."

RESULTS

The mean and percentage prevalence of the each lesion recorded and agreed by six examiners among 60 subjects showed presence of 87.77% hyperpigmented areas, 64.44% depigmented areas, 51.66% excrescences, 32.22% potentially malignant lesions and 9.72% frank ulcerations.

CONCLUSION

Reverse smoking is an endemic tobacco habit still practiced in the coastal rural Andhra Pradesh. It is a well-established and socially acceptable habit among adult females. The changes recorded clinically shows characteristic features that are unique among this population group.

Expression of Podoplanin in Different Grades of Oral Squamous Cell Carcinoma

Background:

The expression of podoplanin is up-regulated in a number of different human cancers, including squamous cell carcinoma of the oral cavity and its relationship with tumor invasion raises the possibility that podoplanin expression could be used as a biomarker for diagnosis and prognosis.

Aim:

The aim of the present study is to evaluate the expression of podoplanin in different grades of squamous cell carcinoma (SCC) and to correlate the expression of podoplanin with relevant clinical features such as age, sex, site and associated habits.

Materials and Methods:

Retrospective study was carried on formalin fixed, paraffin embedded blocks of oral SCC (OSCC) from the archives of Department of Oral and Maxillofacial Pathology, Vishnu Dental College, Bhimavaram. Thirty diagnosed cases were included, of which 10 were well-differentiated SCC (WDSCC) (n = 10), 10 moderately DSCC and 10 poorly DSCC. Demographics including age, sex, gender and associated habit history, were recorded. Immunohistochemical staining was done with podoplanin anti D2–40 antibody, for all the cases of OSCC and assessed qualitatively. The data obtained were tabulated and subjected to statistical analysis.

Results:

In the present study, 27 cases of SCC showed podoplanin expression and remaining three cases showed no expression. The scoring criterion suggested by Yuan et al. was followed for semi-quantitative assessment. OSCC, seven cases presented weak expression (Immunoreactive score [IRS] 0–3), 15 presented moderate expression (IRS Score 4–7) and 5 presented high expression (IRS Score > 8). The assessment of podoplanin expression in the cytoplasm, the membrane and the cytoplasm and membrane (both) of tumor cells showed overall high positivity in the cytoplasmic followed by both and the membrane.

Conclusion:

Podoplanin could be a potent biomarker in assessing the cytoplasm/membrane staining of tumor cells. Furthermore, a high level of podoplanin expression is suggestive of high frequency of lymph node metastasis and immature status in the differentiation process of OSCC.

Sequential projection-based metacognitive learning in a radial basis function network for classification problems

In this paper, we present a sequential projection-based metacognitive learning algorithm in a radial basis function network (PBL-McRBFN) for classification problems. The algorithm is inspired by human metacognitive learning principles and has two components: a cognitive component and a metacognitive component. The cognitive component is a single-hidden-layer radial basis function network with evolving architecture. The metacognitive component controls the learning process in the cognitive component by choosing the best learning strategy for the current sample and adapts the learning strategies by implementing self-regulation. In addition, sample overlapping conditions and past knowledge of the samples in the form of pseudosamples are used for proper initialization of new hidden neurons to minimize the misclassification. The parameter update strategy uses projection-based direct minimization of hinge loss error. The interaction of the cognitive component and the metacognitive component addresses the what-to-learn, when-to-learn, and how-to-learn human learning principles efficiently. The performance of the PBL-McRBFN is evaluated using a set of benchmark classification problems from the University of California Irvine machine learning repository. The statistical performance evaluation on these problems proves the superior performance of the PBL-McRBFN classifier over results reported in the literature. Also, we evaluate the performance of the proposed algorithm on a practical Alzheimer's disease detection problem. The performance results on open access series of imaging studies and Alzheimer's disease neuroimaging initiative datasets, which are obtained from different demographic regions, clearly show that PBL-McRBFN can handle a problem with change in distribution.

Effect of copper- and zinc-methionine supplementation on bioavailability, mineral status and tissue concentrations of copper and zinc in ewes

The effect of feeding Cu- and Zn-methionine to ewes was studied in a 240d feeding trial. The plasma and tissue Cu and Zn concentrations and Cu/Zn-superoxide dismutase (Cu/Zn-SOD) activity were employed to assess the relative bioavailability from Cu- and Zn-methionine. The macro and micronutrient intake, utilization, plasma mineral status, tissue accumulation of Cu and Zn as well as wool concentration of Cu and Zn were studied in ewes (n=12) fed a corn-soybean meal based basal diet with 50% more Cu and Zn supplementation over the basal diet either from Cu- and Zn-sulfate (Cu-Sulf+Zn-Sulf group) or Cu- and Zn-methionine (Cu-Meth+Zn-Meth group). The average daily feed intake and body weight gain of ewes did not differ due to dietary supplementation of Cu- and Zn-methionine. However, dry matter intake was comparatively lower and thus resulted in better feed: gain in Cu- and Zn-methionine group as compared to ewes fed Cu- and Zn-sulfate. Supplementation of Cu and Zn over the basal diet either from methionine-chelated or sulfate sources resulted in increased plasma Cu and Zn as well as Cu/Zn-SOD activity on d-30, which indicated a positive correlation between plasma Cu and Zn and Cu/Zn-SOD activity. The gut absorption, liver concentrations of Cu and Zn, and liver Cu/Zn-SOD activity were significantly (P<0.01) higher in ewes supplemented with Cu- and Zn-methionine compared to Cu- and Zn-sulfate. Periodical analysis of wool samples indicated no significant difference in Cu and Zn content between Cu-and Zn-methionine and Cu- and Zn-sulfate groups. Feeding of Cu and Zn from methionine-chelated source resulted in reduced (P<0.01) excretion of Cu and Zn in feces indicating their better utilization, and this will have positive implication on environment. The gut absorption values, plasma and liver tissue concentrations of Cu and Zn supported the hypothesis that Cu- and Zn-methionine supplements have better bioavailability compared to Cu- and Zn-sulfate and Cu- and Zn-dependent enzyme (Cu/Zn-SOD) could be used to determine the bioavailability of Cu and Zn.

Tubifex: a sensitive model for UV-B-induced phototoxicity

The natural increase of UV-B radiation levels due to depletion of the ozone layer in the atmosphere may impose additional stress for the survival of zooplanktons which serve as a major constituent of the aquatic food chain. To study the adverse effects of UV-B radiation on the aquatic biomass, studies were conducted using the aquatic organism Tubifex as a model, as UV-B radiation is known to penetrate into the natural waters. UV-B radiation induced mortality in tubifex and the production of activated oxygen species by these organisms. Alterations in DNA, RNA, protein, glutathione (GSH), hydrogen peroxide H(2)O(2), thiobarbituric acid-reactive substance (TBA-RS), ATPase, AChE, GST, and LDH activities in Tubifex at various doses (0-2.0 J) of UV-B radiation were found. LC(50) value for UV-B-induced mortality of Tubifex was 0.80+/-0.15 J and the threshold dose was 0.35+/-0.05 J; mortality began within 3h postirradiation. UV-B dose-dependent production of singlet oxygen, superoxide anion, and hydroxyl radicals by Tubifex was observed. DNA, RNA, protein, and GSH contents were found to decrease significantly (P<0.001) while H(2)O(2) and TBA-RS increased (P<0.01) under the influence of UV-B radiation. The activities of ATpase, AChE, and GST enzymes were inhibited (P<0.01) and LDH activity was significantly increased (P<0.001) in Tubifex exposed to UV-B radiation. The results suggest that an increase in UV-B radiation alters several biochemical processes, leading to the mortality of the organism. Tubifex could be useful as a sensitive alternate model for studying UV-B-induced phototoxicity and possible mechanisms of action.

EVALUATION OF UV-INDUCED SUPEROXIDE RADICAL GENERATION POTENTIAL OF SOME COMMON ANTIBIOTICS

Photosensitization reaction of drugs leading to the formation of reactive oxygen species (ROS) cause tissue injury causing damage to various cellular macromolecules. The aim of this study was to determine the superoxide anion (O2-) generation potential of commonly used antibiotics so that due precaution could be exercised to minimize their photosensitizing action and oxidative stress potential. The selected antibiotics were examined for their ability to produce (O2-) under sunlight and artificial UVA (320-400 nm) and UVB (290-320 nm). Lincomycin, cephalothin and erythromycin generated significant amount of O2- under various irradiation conditions. Superoxide dismutase (SOD), an enzymatic quencher of O2- inhibited O2- production in all drugs tested. The results suggest that due precaution are necessary to avoid ultraviolet radiation (UVR) after the intake of photoreactive drugs, especially in tropical and sub tropical countries.

Effect of lindane on the growth and metabolic activities of cyanobacteria

The effect of lindane was studied in Cyanobacteria (Anabaena) by estimating its growth pattern, biomass yield, chlorophyll content, and total starch and protein content. The results reveal that exposure of Anabaena with 0.5, 1.0, 1.5, and 2.0 ppm levels of lindane will have drastic effects on biomass production and photosynthetic rate. Since Cyanobacteria are a primary source of aquatic food web and important biofertilizer for rice cultivation, their protection from residual effects of lindane is essential for enriched soil fertility.

Sensitivity of duckweed (Lemna major) to ultraviolet-B radiation

The sensitivity of an important aquatic macrophyte, duckweed (Lemna major), to UV-B radiation was studied under experimental conditions at three different doses designated as no, mild, and severe injury dose by observing visible injury symptoms and estimating levels of chlorophyll, pheophytin, carotenoids, protein, starch, free sugar, and peroxidase activity. Laboratory-grown duckweed plants were exposed to UV-B radiation at 0.4 mW/cm(2) intensity for different time periods. Mild and severe injury were developed at 6.48 and 8.64 J, respectively. Peroxidase activity increased at all the exposure levels. Dose-dependent decrease in chlorophyll and starch with drastic depletion in protein and free sugar content were observed. Pheophytin and carotenoids content increased at no injury level, but decreased at higher exposure level. The results indicate that ambient UV-B radiation at the indicated level acts as a physiological stress in Lemna major.

Agricultural produce in the dry bed of the River Ganga in Kanpur, India--a new source of pesticide contamination in human diets

Vegetables grown in the dry bed field of the River Ganga in Kanpur, an important industrial city of North India, were analysed for the pesticides hexachlorocyclohexane (HCH), dichlorodiphenyl trichloroethane (DDT), their isomers and metabolites at three different sites. Residues of both the pesticides were found in all the samples. Mean levels of 109.35, 136.76 and 145.93 microg HCH/kg and 6.64, 49.3 and 46.70 microg DDT/kg were found in the rural upstream, city and downstream industrial areas, respectively. The mean total HCH and DDT levels were within safe limits as per the Indian Standard but some samples had HCH levels above the WHO/FAO limit. The pesticide residue level in vegetables was several fold higher than their surrounding sandy soil and could pose health problems since these popular vegetables are consumed regularly by the population.

UVB-induced reduction in biomass and overall productivity of cyanobacteria

Effect of middle wave ultraviolet radiation (UVB) was studied in three different species of cyanobacteria (Nostoc, Anabaena and Scytonema) by estimating their growth pattern, biomass yield, chlorophyll content, total starch and protein content. The results show that exposure of the cyanobacteria with UVB dose corresponding to an increase or decrease of 20% in its environmental flux will have drastic effects on biomass production, photosynthetic rate and nitrogen fixation. Cyanobacteria are primary sources of marine food web and an important biofertilizer; therefore, their protection from increasing threat of stratospheric ozone depletion will be necessary to maintain the ecological balance.