Comparison of Astigmatic Correction after Femtosecond Lenticule Extraction and Small-Incision Lenticule Extraction for Myopic Astigmatism

Purpose

To compare postoperative astigmatic correction between femtosecond lenticule extraction (FLEx) and small-incision lenticule extraction (SMILE) in eyes with myopic astigmatism.

Methods

We examined 26 eyes of 26 patients undergoing FLEx and 26 eyes of 26 patients undergoing SMILE to correct myopic astigmatism (manifest astigmatism of 1 diopter (D) or more). Visual acuity, cylindrical refraction, the predictability of the astigmatic correction, and the astigmatic vector components using Alpin’s method, were compared between the two groups 3 months postoperatively.

Results

We found no statistically significant difference in manifest cylindrical refraction (p=0.74) or in the percentage of eyes within ± 0.50 D of their refraction (p=0.47) after the two surgical procedures. Moreover, no statistically significant difference was detected between the groups in astigmatic vector components, namely, surgically induced astigmatism (0.80), target induced astigmatism (p=0.87), astigmatic correction index (p=0.77), angle of error (p=0.24), difference vector (p=0.76), index of success (p=0.91), flattening effect (p=0.79), and flattening index (p=0.84).

Conclusions

Both FLEx and SMILE procedures are essentially equivalent in correcting myopic astigmatism using vector analysis, suggesting that the lifting or non-lifting of the flap does not significantly affect astigmatic outcomes after these surgical procedures.     

Association of Allergic Symptoms with Dengue Infection and Severity: A Systematic Review and Meta-analysis

The relationship between the severity of dengue infection and allergy is still obscure. We conducted an electronic search across 12 databases for relevant articles reporting allergic symptoms, dengue infection, and dengue classification. These studies were categorized according to dengue severity and allergy symptoms, and a meta-analysis was performed by pooling the studies in each category. Among the included 57 articles, pruritus was the most common allergic sign followed by non-specified allergy and asthma(28.6%, 13%, and 6.5%, respectively). Despite the reported significant association of dengue with pruritus and total Ig E level(P \ 0.05), in comparison with non-dengue cases and healthy controls, there was no association between the different severe dengue group with pruritus, skin allergy, food allergy or asthma. However,removing the largest study revealed a significant association between asthma with dengue hemorrhagic fever(DHF) rather than dengue fever(DF). In comparison with DF, DHF was associated with Ig E positivity. Furthermore, specific-Ig E level was higher in secondary DF rather than primary DF. There was a possible association between allergy symptoms and dengue severity progression. Further studies are needed to clarify this association.     

Luteolin protects against lead acetate-induced nephrotoxicity through antioxidant,anti-inflammatory,anti-apoptotic,and Nrf2/HO-1 signaling pathways

Molecular Biology Reports - Lead (Pb) is one of the most common heavy metal pollutants affecting living organisms. It induces nephrotoxicity with significant alterations in renal structure and...     

Intranasal Microemulsion of Sildenafil Citrate: In Vitro Evaluation and In Vivo Pharmacokinetic Study in Rabbits

The purpose of the present study was to prepare intranasal delivery system of sildenafil citrate and estimate its relative bioavailability after nasal administration in rabbits to attain rapid onset of action with good efficacy at lower doses. Sildenafil citrate saturated solubility was determined in different solvents, cosolvents, and microemulsion systems. For nasal application, sildenafil citrate was formulated in two different systems: the first was a cosolvent system (S3) of benzyl alcohol/ethanol/water/Transcutol/taurodeoxy cholate/Tween 20 (0.5:16.8:47.7:15.9:1:18.1% w/w). The second was a microemulsion system (ME6) containing Oleic acid: Labrasol/Transcutol/water (8.33:33.3:16.66:41.66% w/w). The prepared systems were characterized in relation to their clarity, particle size, viscosity, pH, and nasal ciliotoxicity. In vivo pharmacokinetic performance of the selected system ME6 (with no nasal ciliotoxicity) was evaluated in a group of six rabbits in a randomized crossover study and compared to the marketed oral tablets. The targeted solubility (>20 mg/ml) of sildenafil citrate was achieved with cosolvent systems S1, S3, and S5 and with microemulsion systems ME3–ME6. The saturated solubility of sildenafil citrate in cosolvent system S3 and microemulsion system ME6 were 22.98 ± 1.26 and 23.79 ± 1.16 mg/ml, respectively. Microemulsion formulation ME6 showed shorter t _max (0.75 h) and higher AUC_(0-∞) (1,412.42 ng h/ml) compared to the oral tablets which showed t _max equals 1.25 h and AUC_(0-∞) of 1,251.14 ng h/ml after administration to rabbits at dose level of 5 mg/kg. The relative bioavailability was 112.89%. In conclusion, the nasal absorption of sildenafil citrate microemulsion was found to be fast, indicating the potential of nasal delivery instead of the conventional oral administration of such drug.     

The changing incidence of human papillomavirus-associated oropharyngeal cancer using multiple imputation from 2000 to 2010 at a Comprehensive Cancer Centre

Introduction Human papillomavirus (HPV) is a risk and prognostic factor for oropharyngeal cancer (OPC). Determining whether the incidence of HPV-associated OPC is rising informs health policy. Methods HPV status was ascribed using p16 immunohistochemistry in 683/1474 OPC patients identified from the Princess Margaret Hospital's Cancer Registry (from 2000 to 2010). Missing p16 data was estimated using multiple (n = 100) imputation (MI) and validated using an independent OPC cohort (n = 214). Non-OPC head and neck squamous cell carcinoma (HNSCC) (n = 3262) were also used for time-trend comparison. Regression was used to compare HNSCC subsets and time-trends. The c-index was used to measure the predictive ability of MI. Results The incidence of OPC rose from 23.3% of all HNSCC in 2000 to 31.2% in 2010 (p = 0.002). In the subset of OPC tested for p16, there was no change in p16 positivity over time (p = 0.9). However, p16 testing became more frequent over time (p < 0.0001), but was nonetheless biased, favouring never-smokers [OR 1.87 (95% CI 1.29–2.70)] and tumors of the tonsil [OR 2.30 (1.52–3.47)] or base-of-tongue [OR 1.72 (1.10–2.70)]. These same factors were also associated with p16-positivity [ORs 3.22 (1.27–8.16), 7.26 (3.50–15.1), 5.83 (2.70–12.7), respectively]. Following MI and normalization, the proportion of OPC that was p16-associated rose from 39.8% in 2000 to 65.0% in 2010, p = 0.002, fully explaining the rise in OPC in our patient population. Conclusion The rise in HNSCC referrals seen from 2000 to 2010 at our institution was driven primarily by p16-associated OPC. MI was necessary to derive reliable conclusions when cases with missing data are considerable.     

Metabolic engineering of Propionibacterium freudenreichii: effect of expressing phosphoenolpyruvate carboxylase on propionic acid production

Propionic acid is currently produced mainly via petrochemicals, but there is increasing interest in its fermentative production from renewable biomass. However, the current propionic acid fermentation process suffers from low product yield and productivity. In this work, the gene encoding phosphoenolpyruvate carboxylase (PPC) was cloned from Escherichia coli and expressed in Propionibacterium freudenreichii. PPC catalyzes the conversion of phosphoenolpyruvate to oxaloacetate with the fixation of one CO₂. Its expression in P. freudenreichii showed profound effects on propionic acid fermentation. Compared to the wild type, the mutant expressing the ppc gene grew significantly faster, consumed more glycerol, and produced propionate to a higher final titer at a faster rate. The mutant also produced significantly more propionate from glucose under elevated CO₂ partial pressure. These effects could be attributed to increased CO₂ fixation and resulting changes in the flux distributions in the dicarboxylic acid pathway.     

Assessment of anti-mutagenic,anti-histopathologic and antioxidant capacities of Egyptian bee pollen and propolis extracts

Bee pollen and propolis are popular, traditional health foods. The objective of the current study was to investigate the anti-mutagenic, anti-histopathologic and antioxidant effects among water extracts of Egyptian bee pollen (WEBP) and brown powder of water-soluble derivative propolis (WSDP) on cisplatin (CDDP) induced hepatic, renal, testicular and genotoxicity in male albino mice (Mus muscullus), in addition to their effects on the oxidant/antioxidant status in the tested organs. Hepatic, renal and testicular dysfunctions were evaluated histologically; while genotoxicity and cytotoxicity were evaluated by the bone marrow chromosomal aberration assay and mitotic index, respectively. Moreover, oxidative stress was explored via determination of lipid peroxidation, catalase activity and the concentration of the reduced form of glutathione. The treatment of mice with WEBP and WSDP at doses 140 and 8.4 mg/kg b. wt./day, respectively for 14 days simultaneously with CDDP (2.8 mg/kg b. wt.) resulted in significant protection. The positive control animals taken CDDP alone showed toxic histological and genetical manifestations (at P < 0.05) accompanied with an elevated content of peroxidized lipid and lowered catalase activity and glutathione concentration in the homogenate of liver, kidney and testis tissues (at P < 0.001). These toxic side effects in all tested organs were greatly ablated with a significant reduction in lipid peroxidation level and elevation in catalase activity and glutathione concentration (P < 0.001) when using both WEBP and WSDP. On the basis of the present assays, Bee pollen appears more potent in exerting an ameliorative effect and this effect was more pronounced in testis.     

COMPARATIVE FUNCTIONAL ANALYSES OF ULTRABITHORAX REVEAL MULTIPLE STEPS AND PATHS TO DIVERSIFICATION OF LEGS IN THE ADAPTIVE RADIATION OF SEMI‐AQUATIC INSECTS

Invasion of new ecological habitats is often associated with lineage diversification, yet the genetic changes underlying invasions and radiations are poorly understood. Over 200 million years ago, the semi‐aquatic insects invaded water surface from a common terrestrial ancestor and diversified to exploit a wide array of niches. Here, we uncover the changes in regulation and function of the gene Ultrabithorax associated with both the invasion of water surface and the subsequent diversification of the group. In the common ancestor of the semi‐aquatic insects, a novel deployment of Ubx protein in the mid‐legs increased their length, thereby enhancing their role in water surface walking. In derived lineages that specialize in rowing on the open water, additional changes in the timing of Ubx expression further elongated the mid‐legs thereby facilitating their function as oars. In addition, Ubx protein function was selectively reversed to shorten specific rear‐leg segments, thereby enabling their function as rudders. These changes in Ubx have generated distinct niche‐specialized morphologies that account for the remarkable diversification of the semi‐aquatic insects. Therefore, changes in the regulation and function of a key developmental gene may facilitate both the morphological change necessary to transition to novel habitats and fuel subsequent morphological diversification.