Clinical Study of Focus NIGHT &DAY® contact lenses

Objectives: To investigate the visual and ocular implications of continuous wearing a silicon hydrogel contact lens for up to 3 weeks , in a dry semi-arid climate environment. Methods: Clinical examination of eye conditions (visual acuity, Schirmer test, corneal thickness and endothelial cells counts) for 9 healthy voluntary students was carried out between September and November of 2004 in Riyadh\'s King Saud University clinical facilities, using Ciba Vision\'s ocus Day & Night® lotrafilcon lenses. Which is measured weekly for 3 weeks. Results: Visual acuity testing revealed no significant changes after three weeks of continuous wear of the Focus lens. An average minimum angle of resolution (MAR) of 1.045 min arc was maintained throughout the 3 weeks. No significant drop had been recorded (p>0.05). The Schirmer test for eye lubrication showed an overall decrease in the wetting of the strip from about 36 mm to around 27 mm. Corneal thickness for the 9 subjects perior to CL wearing was 0.529 ± 0.050 mm, slightly increased to 0.533 ± 0.044 mm at the end of the study. The mean cell area value was 359 ± 67 Um2 at first visit, becoming only marginally higher at 361 ± 71 Um2 after three weeks of contact lens wear. Conclusion: The Focus NIGHT & DAY® lenses can be worn safely as extended-wear contact lenses for up to 3 weeks without ocular complications. Visual acuity, tear functions or corneal structure are not altered. Keywords: optometry, silicone hydrogel materials, resolution, ocular.Sudan Journal of Medical Sciences Vol. 3 (2) 2008: pp. 115-12

POTENTIAL ROLE OF CARICA PAPAYA AND THEIR ACTIVE CONSTITUENTS IN THE PREVENTION AND TREATMENT OF DISEASES

Natural products or products from the plant source show pivotal role in the diseases prevention and treatment since ancient. Numerous plants and their ingredients such as Nigella sativa, curcumin, olive and dates fruits have proven health promoting effects. In this vista, Papaya (C. Papaya family Caricaceae) is a medicinal plant that has been extensively used in traditional medicine due to their versatile approach in diseases treatment and prevention. The health-promoting activities of papaya and their constituents are recognized due to antioxidant activity. C. Papaya holds a range of valuable constituents such as vitamin, flavonoids and minerals in the different parts of plants and each constituent shows role in the disease management. Earlier reports have proven that C. papaya fruits and its ingredients shows role in health management via prevention of the pathogenesis of diseases. Its leaf juice also contains significant constituents, and they shows very effective role in the management of dengue fever with platelet increasing property. In this review, we aimed to evaluate the applications of papaya in cancer, diabetes, wound healing, malaria, dengue fever and other various disease prevention and treatment.Â

FICUS CARICA AND ITS CONSTITUENTS ROLE IN MANAGEMENT OF DISEASES

Alternative medicines or formulation based on natural sources are good option in diseases cure and prevention. Ficus carica is member of Moraceae family and its health management properties have been mentioned in religious books and traditional medicines. It holds various constituents including phenolic compounds, minerals and vitamins and such ingredient shows role in disease cure. Studies based on in vivo and in vitro reported that figs fruits, stem, leaves, and latex have health management effect through antioxidant, anti-inflammatory effects, antimicrobial, anticarcinogenic, and anti-inflammatory effects. Moreover, an inverse correlation between figs use and development of disease has been noticed. Despite its implications in disease management, little is known about their mechanism of action. In this review, efforts are made based on in vivo and in vitro studies to illuminate the role of F. carica leaves and fruits in the prevention of diseases

ROLE OF GREEN TEA AND ITS CONSTITUENT EPIGALLOCATECHIN-3-GALLATE IN THE HEALTH MANAGEMENT

Green tea and its constituents is natural beverage used worldwide especially in Asian countries and also used as natural medicine for thousands of years. The current approaches for diseases treatment based on allopathic drugs offer restricted options, adverse effect and also show alterations in biochemical and genetic pathways. Considerable achievement on green tea and its constituents has been made based on experimental studies to confirm its mechanism of action in disease modulation but the exact mechanism still under investigation. It is thought that, green tea is rich in antioxidant and shows a pivotal role in the scavenging of free radical generation and prevention of disease pathogenesis. However, further studies are needed to confirm the safe dose and the exact mechanism of action in relation to health management. In the present review, an attempt has been made to explore the role of green tea in diseases prevention and its approach on modulation of various biochemical and physiological process.Â

Novel antibacterial activity of Terfizia claveryi aqueous extract against clinical isolates of corneal ulcer

Terfizia claveryi was examined for in vitro antibacterial activity using the disc diffusion, well diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). T.claveryi exhibited excellent antibacterial activity against all clinical isolates of corneal ulcer tested, especially against Pseudomonas aeruginosa which showed the maximum antibacterial activity with mean zone of inhibition 20.33 mm at concentration of 100 mg/ml. The MIC for Staphylococcus aureus ranged from 0.040-1.250 mg/ml and MBC for Escherichia coli was 75 μl/ml. In the present study, the MIC value of the active aqueous extract were lower than the MBC values suggesting that, T. claveryi aqueous extracts were bacteriostatic at lower concentration but bactericidal at higher concentration. Also, the bacterial zone of inhibition increased with the increasing concentration of T. claveryi aqueous extract. To the best of our knowledge, this is the first report for the novel antibacterial activity of T.claveryi aqueous extract. This active compound may be used as alternative therapeutic drug for the control of corneal infections. However, further research is needed to examine its in vivo mechanism of action, toxicity, and therapeutic effect.Key words: Bacteria, corneal infection, antimicrobials, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), Terfizia claveryi

The effect of vascular endothelial growth factor in the progression of bladder cancer and diabetic retinopathy

Abstract: Bladder cancer and diabetic retinopathy is a major public health and economical burden worldwide. Despite its high prevalence, the molecular mechanisms that induce or develop bladder carcinomas and diabetic retinopathy progression are poorly understood but it might be due to the disturbance in balance between angiogenic factors such as VEGF and antiangiogenic factors such as pigment epithelium derived growth factor. VEGF is one of the important survival factors for endothelial cells in the process of normal physiological and abnormal angiogenesis and induce the expression of antiapoptotic proteins in the endothelial cells. It is also the major initiator of angiogenesis in cancer and diabetic retinopathy, where it is up-regulated by oncogenic expression and different type of growth factors. The alteration in VEGF and VEGF receptors gene and overexpression, determines a diseases phenotype and ultimately the patient's clinical outcome. However, expressional and molecular studies were made on VEGF to understand the exact mechanism of action in the genesis and progression of bladder carcinoma and diabetic retinopathy , but still how VEGF mechanism involve in such type of disease progression are not well defined. Some other factors also play a significant role in the process of activation of VEGF pathways. Therefore, further detailed analysis via molecular and therapeutic is needed to know the exact mechanisms of VEGF in the angiogenesis pathway. The detection of these types of diseases at an early stage, predict how it will behave and act in response to treatment through regulation of VEGF pathways. The present review aimed to summarize the mechanism of alteration of VEGF gene pathways, which play a vital role in the development and progression of bladder cancer and diabetic retinopathy

The S-cone PhNR and pattern ERG in primary open angle glaucoma

PURPOSE. To compare the sensitivity of the photopic negative response (PhNR) from the shortwave (S)-sensitive and the long (L)- and medium (M)-wave–sensitive cone electroretinograms (ERGs), with the pattern electroretinogram (PERG) in the early stages of primary open-angle glaucoma (POAG). METHODS. Eighteen patients under treatment for diagnosed POAG and 19 normal control subjects were investigated. Scone ERGs were elicited using adaptation to 650-nm light to suppress L-cone activity, and substitution between 450 nm and 535 nm to silence M-cone response at luminances higher than rod saturation. PhNRs from the L&M-cone pathways were elicited by a 200-msec pulse of red light (650 nm) on a continuous blue (450 nm) background. PERGs were recorded in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standard. RESULTS. Each method showed a statistically significant difference in the two groups. The S-cone PhNR was the most sensitive test and provided the most statistically significant results, with the largest area enclosed by the receiver operating characteristic (ROC) curve. CONCLUSIONS. The findings indicate that all three types of ERG may be useful in glaucoma investigation. The L- and M-cone PhNRs may have a role in monitoring established glaucoma. The previously reported high sensitivity of the PERG was confirmed. Extensive diffuse damage to S-cone bipolar and bistratified ganglion cells appears to occur at a very early stage in POAG, owing to a pressure-related mechanism, and the S-cone PhNR was the most sensitive test. It may in future have an important role in diagnosis and monitoring of early glaucoma. Further investigation of this possibility is recommende

The effect of bleach duration and age on the ERG photostress test

Background: The ERG photostress test assesses the recovery of the focal 41 Hz ERG following exposure to a bright light that bleaches a significant proportion of photopigment. The aims of this study were: 1) to compare the repeatability of the ERG photostress test recovery time constant following long and short duration light exposure, and 2) to determine the effect of age on the ERG photostress test recovery time constant. Methods: Focal 41 Hz ERGs were recorded from 23 participants (age range 20–71 years) at 20-second intervals for 5 minutes following either a short-duration (photoflash) or long-duration (equilibrium) light exposure. After a 5-minute wash-out period, the procedure was repeated using the second bleach modality. The time constant of cone recovery was determined by fitting an exponential model to the amplitude recovery data. The whole procedure was repeated on a second occasion. The co-efficient of repeatability (CoR) was calculated for each bleaching technique. The relationship between the time constant of recovery and age was investigated (Pearson’s correlation coefficient). Results: The time constant of recovery following an equilibrium bleach was more repeatable than recovery following a photoflash (CoR = 85s and 184s respectively). Eight trials (from seven participants) failed to show a reduction in amplitude following the photoflash, suggesting that a blink or fixation loss had occurred. All participants were reliably light-adapted by the equilibrium bleach. For the equilibrium bleach data, the time constant of recovery increased with age at a rate of 27 seconds per decade. Conclusions: The equilibrium bleach was more reliable and repeatable than the photoflash. Increasing participant age was shown to result in a lengthening of the recovery time constant, of a magnitude comparable to previously published psychophysical data

Diels Alder-mediated release of gemcitabine from hybrid nanoparticles for enhanced pancreatic cancer therapy

Abstract Hybrid nanoparticles (HNPs) have shown huge potential as drug delivery vehicles for pancreatic cancer. Currently, the first line treatment, gemcitabine, is only effective in 23.8% of patients. To improve this, a thermally activated system was developed by introducing a linker between HNPs and gemcitabine. Whereby, heat generation resulting from laser irradiation of the HNPs promoted linker breakdown resulting in prodrug liberation. In vitro evaluation in pancreatic adenocarcinoma cells, showed the prodrug was 4.3 times less cytotoxic than gemcitabine, but exhibited 11-fold improvement in cellular uptake. Heat activation of the formulation led to a 56% rise in cytotoxicity causing it to outperform gemcitabine by 26%. In vivo the formulation outperformed free gemcitabine with a 62% reduction in tumor weight in pancreatic xenografts. This HNP formulation is the first of its kind and has displayed superior anti-cancer activity as compared to the current first line drug gemcitabine after heat mediated controlled release