Scoring Of Pain Perception During Phacoemulsification Under Topical Anaesthesia.

BACKGROUND: Topical anaesthesia is safe and inexpensive type of anaesthesia used during phacoemulsification as compared to local anaesthesia. The trend of conducting surgeries under topical anaesthesia is increasing globally. The objective of this study was to determine the perception of severity of pain during phacoemulsification using topical anaesthesia. METHODS: This descriptive cross-sectional study was conducted at Jinnah International Hospital Abbottabad for a period of one year and included 196 patients of posterior subcapsular cataracts. Data was collected on a pretested structured questionnaire and analysed by SPSS version 20. Chi square test was used to find association between variables and p-value of equal or less than 0.05 was considered significant. RESULTS: The mean age of the patients was 60.43±14.63 years. Out of 196 patients, 110 (56.1%) were males and 86 (43.9%) were females. During surgery pain score was 0 (no pain) in 149 (76%), 1 (mild) in 14 (7.1%), 2 (moderate) in 15 (7.7%) and 3 (severe) in 18 (9.2%) patients. Pain score was found to be significantly associated with gender (p=0.003) and age group (p=0.008). CONCLUSIONS: Phacoemulsification can be safely performed under topical anaesthesia in patients with posterior subcapsular cataracts with minimum intraoperative pain perception by the patients.

Mechanism Of Nephroprotection By Picrorhiza Kurroa.

BACKGROUND: Humans are exposed either deliberately or unintentionally to a variety of diverse chemicals that harm the kidney. To reduce the alarming high incidence of nephrotoxicity, some chemical as well as herbal alternatives are needed. Nimesulide belongs to a group of antiinflammatory drugs that are in common use in our society. Like all non-steroidal antiinflammatory drugs, it carries a potential threat of nephrotoxicity especially when other risk factors are present in user. The objective of this study was to find herbal alternative with antiinflammatory and nephroprotective qualities and to bring into light its mechanism of nephroprotection. METHODS: This experimental study was conducted on mice at National Institute of Health, Islamabad from Feb 2013 to March 2014. Nimesulide was given in a dosage of 750 mg/kg body weight for 3 days to induce nephrotoxicity and protective effect of Picrorhiza kurroa was noted in two doses of 250 mg/kg and 500 mg/kg for 14 days. Renal function tests were done and urinary PGE2 was measured to assess the effect of nimesulide and Pk on kidneys. RESULTS: In our study, significant improvement was seen in serum urea and creatinine levels in mice receiving low and high dose Picrorhiza kurroa. However, no significant improvement was noted in urinary PGE2 showing that the mechanism of nephroprotection is not by vasodilatory effect of Pk. CONCLUSIONS: This study showed nimesulide nephrotoxic potential and Pk is a good herbal antiinflammatory and nephroprotective alternative for nimesulide but its mechanism of nephroprotection is not by PGE2.

EVALUATION OF THERAPEUTIC POTENTIAL OF PICRURHIZA KURROA GLYCOSIDAL EXTRACT AGAINST NIMESULIDE NEPHROTOXICITY: A PILOT STUDY.

BACKGROUND: Picrorhiza kurroa (Pk) is a traditional Ayurvedic herb famous as a potent bepatoprotective agent, only few studies are available on the nephroprotective activity of this herb. The objective of this pilot study was to determine the therapeutic effectiveness of Pk against nimesulide induced toxicity. METHODS: This laboratory based experimental study was conducted on mice at National Institute of Health, Islamabad from Dec 2012 to Jan 2013. The mice were divided in to 4 groups. One group was given only PK while the other three groups were given nimesulide in a dosage of 750 mg/kg body weight for 3 days to induce nephrotoxicity and protective effect of Pk was noted by giving 250 mg/kg and 500 mg/kg pk for 14 days to the two of the nimesulide induced nephrotoxicity groups. Biochemical assessment of kidney was done by measuring serum urea & creatinine. Also histology was done to confirm the findings of biochemical assessment. RESULTS: In our pilot study out of 20 mice, 19 mice survived. Only 1 mouse of nimesulide group died. Mean serum urea of nimesulide group was 60 mg/dl and was decreased to 23 mg/dI and 25 mg/dl by two doses of Pk. Mean creatinine in group 2 was 0.55 mg/dl and was decreased to 0.21 and 0.19 mg/dl by two doses of Pk. CONCLUSION: Our study shows that nimesulide is a potential nephrotoxic drug and its toxic effects on kidney can be minimized by using glycosidal extract of Pk.

Circular polarization vision in a stomatopod crustacean.

We describe the addition of a fourth visual modality in the animal kingdom, the perception of circular polarized light. Animals are sensitive to various characteristics of light, such as intensity, color, and linear polarization [1, 2]. This latter capability can be used for object identification, contrast enhancement, navigation, and communication through polarizing reflections [2-4]. Circularly polarized reflections from a few animal species have also been known for some time [5, 6]. Although optically interesting [7, 8], their signal function or use (if any) was obscure because no visual system was known to detect circularly polarized light. Here, in stomatopod crustaceans, we describe for the first time a visual system capable of detecting and analyzing circularly polarized light. Four lines of evidence-behavior, electrophysiology, optical anatomy, and details of signal design-are presented to describe this new visual function. We suggest that this remarkable ability mediates sexual signaling and mate choice, although other potential functions of circular polarization vision, such as enhanced contrast in turbid environments, are also possible [7, 8]. The ability to differentiate the handedness of circularly polarized light, a visual feat never expected in the animal kingdom, is demonstrated behaviorally here for the first time.

Interspecific and intraspecific views of color signals in the strawberry poison frog Dendrobates pumilio.

Poison frogs in the anuran family Dendrobatidae use bright colors on their bodies to advertise toxicity. The species Dendrobates pumilio Schmidt 1858, the strawberry poison frog, shows extreme polymorphism in color and pattern in Panama. It is known that females of D. pumilio preferentially choose mates of their own color morph. Nevertheless, potential predators must clearly see and recognize all color morphs if the aposematic signaling system is to function effectively. We examined the ability of conspecifics and a model predator to discriminate a diverse selection of D. pumilio colors from each other and from background colors. Microspectrophotometry of isolated rod and cone photoreceptors of D. pumilio revealed the presence of a trichromatic photopic visual system. A typical tetrachromatic bird system was used for the model predator. Reflectance spectra of frog and background colors were obtained, and discrimination among spectra in natural illuminants was mathematically modeled. The results revealed that both D. pumilio and the model predator discriminate most colors quite well, both from each other and from typical backgrounds, with the predator generally performing somewhat better than the conspecifics. Each color morph displayed at least one color signal that is highly visible against backgrounds to both visual systems. Our results indicate that the colors displayed by the various color morphs of D. pumilio are effective signals both to conspecifics and to a model predator.