Thermodynamics of the Association of Aminoglycoside Antibiotics with Human Angiogenin

BACKGROUND

The body needs to maintain a firm balance between the inducers and inhibitors of angiogenesis, the process of proliferation of blood vessels from pre-existing ones. Human angiogenin (hAng), being a potent inducer of angiogenesis, is a cause of tumor cell proliferation, therefore its inhibition becomes a vital area of research. Aminoglycosides are linked ring systems consisting of amino sugars and an aminocyclitol ring and are in use in clinical practices for a long time. These compounds have found clinical uses as antibacterial agents that inhibit bacterial protein synthesis.

OBJECTIVE

Gentamycin C1, Kanamycin A, Neomycin B, Paromomycin I, and Streptomycin A are commonly used aminoglycoside antibiotics that have been used for the present study. Among these, Neomycin has reported inhibitory activity against angiogenin-induced angiogenesis on the chicken chorioallantoic membrane. This study focuses on the thermodynamic parameters involved in the interactions of these antibiotics with hAng.

METHODS

Agarose gel-based assay, Fluorescence quenching studies and Docking studies.

RESULTS

Anti-ribonucleolytic effect of the antibiotics was observed qualitatively using an agarose gelbased assay, which shows that Neomycin exhibits the most efficient inhibition of hAng. Fluorescence quenching studies at different temperatures, using Stern-Volmer and van't Hoff equations provide information about the thermodynamics of binding, which furthermore highlights the higher binding constant of Neomycin. Docking studies showed that the antibiotics preferably interact with the nuclear translocation site, except Streptomycin, which shows affinity towards the ribonucleolytic site of the protein with very less affinity value.

CONCLUSION

The study has shown the highly spontaneous formation of Neomycin-hAng complex, giving an exothermic reaction with increase in the degree of freedom of the protein-ligand complex.

Non-enzymatic glycation of human angiogenin: Effects on enzymatic activity and binding to hRI and DNA

The effects of non-enzymatic glycation on the structural and functional properties of human angiogenin (hAng) have been investigated with respect to the formation of advanced glycated end products (AGEs), on prolonged treatment with d-Glucose, d-Fructose and d-Ribose at 37 °C. Fluorescence studies show the formation of fluorescent AGEs which exhibit emission maxima at 406 nm and 435 nm. Glycation of hAng with ribose leads to the maximum loss of its functional characteristic properties, as compared to fructose and glucose, along with the formation of higher oligomers. An increase in the incubation time results in the formation of higher oligomers with a concomitant decrease in the ribonucleolytic activity. The increase in the hydrodynamic radii of the glycated samples compared to native hAng is indicative of structural perturbations. The ribonucleolytic activity and the DNA binding ability of glycated hAng has been investigated by an agarose gel-based assay. Glycated hAng was unable to bind with human placental ribonuclease inhibitor (hRI), otherwise known to form one of the strongest protein-protein interaction systems with an affinity in the femtomolar range.

Enhancement of angiogenin inhibition by polyphenol-capped gold nanoparticles

Angiogenin (Ang), is a ribonucleolytic protein that is associated with angiogenesis, the formation of blood vessels. The involvement of Ang in vascularisation makes it a potential target for the identification of compounds that have the potential to inhibit the process. The compounds may be assessed for their ability to inhibit the ribonucleolytic activity of the protein and subsequently blood vessel formation, a crucial requirement for tumor formation. We report an inhibition of the ribonucleolytic activity of Ang with the gallate containing green tea polyphenols, ECG and EGCG that exhibits an increased efficacy upon forming polyphenol-capped gold nanoparticles (ECG-AuNPs and EGCG-AuNPs). The extent of inhibition was confirmed using an agarose gel-based assay followed by fluorescence titration studies that indicated a hundred fold stronger binding of polyphenol-capped gold nanoparticles (GTP-AuNPs) compared to the bare polyphenols. Interestingly, we found a change in the mode of inhibition from a noncompetitive type to a competitive mode of inhibition in case of the GTP-AuNPs, which is in agreement with the 'n' values obtained from the fluorescence quenching studies. The effect on angiogenesis has also been assessed by the chorioallantoic membrane (CAM) assay. We find an increase in the inhibition potency of GTP-AuNPs that could find applications in the development of anti-angiogenic compounds.

Effect of surfactant on quality and performance attributes of topical semisolids

Surfactants are the most common inactive ingredients used in topical drug products. Surfactants in topical products play many functional roles such as emulsifiers, permeation enhancers, and solubilizers. This study was aimed to evaluate the influence of incremental change in the concentration of a surfactant (tween 80) on the quality attributes and performance of semisolid topical products. Four creams were prepared using metronidazole as a model drug using the same manufacturing protocol and similar composition except for the concentration of tween 80, which was increased by 5% w/w across SF1 to SF4. The quality attributes like globule size, pH, drying rate, and in-vitro permeation profile were characterized. The critical quality attributes did not differ significantly across the products. However, there was a significant difference in the permeation profile of the products. The permeation flux (J_max) varied from SF1 to SF4 (51.25 ± 35.29 to 307.98 ± 138.89 ng/cm²/h, respectively). The reason for the difference in the performance of products despite having consistent quality attributes was investigated. One of the major reasons was found to be the difference in the time course of degree of saturation of drug during the evaporative metamorphosis. This study confirms that the time course of degree of saturation is one of the important quality attributes of the topical product that could influence bioavailability and performance of topical products.

Positional preferences in flavonoids for inhibition of ribonuclease A: Where "OH" where?

Flavonoids are a class of polyphenols that possess diverse properties. The structure-activity relationship of certain flavonoids and resveratrol with ribonuclease A (RNase A) has been investigated. The selected flavonoids have a similar skeleton and the positional preferences of the phenolic moieties toward inhibition of the catalytic activity of RNase A have been studied. The results obtained for RNase A inhibition by flavonoids suggest that the planarity of the molecules is necessary for effective inhibitory potency. Agarose gel electrophoresis and precipitation assay experiments along with kinetic studies reveal K_i values for the various flavonoids in the micromolar range. Minor secondary structural changes of RNase A were observed after interaction with the flavonoids. An insight into the specific amino acid involvement in the binding of the substrate using docking studies is also presented. The dipole moment of the flavonoids that depends on the orientation of the hydroxyl groups in the molecule bears direct correlation with the inhibitory potency against RNase A. The direct association of this molecular property with enzyme inhibition can be exploited for the design and development of inhibitors of proteins.

Beyond Tympanomastoidectomy: A Review of Less Common Postoperative Temporal Bone CT Findings

Postoperative temporal bone imaging after surgical procedures such as ossiculoplasty, tympanomastoidectomy, cochlear implantation, and vestibular schwannoma resection is often encountered in clinical neuroradiology practice. Less common otologic procedures can present diagnostic dilemmas, particularly if access to prior operative reports is not possible. Lack of familiarity with the less common surgical procedures and expected postoperative changes may render radiologic interpretation challenging. This review illustrates key imaging findings after surgery for Ménière disease, superior semicircular canal dehiscence, temporal encephalocele repairs, internal auditory canal decompression, active middle ear implants, jugular bulb and sigmoid sinus dehiscence repair, and petrous apicectomy.

pH-Dependent Nitrotyrosine Formation in Ribonuclease A is Enhanced in the Presence of Polyethylene Glycol (PEG)

Protein nitration can occur as a result of peroxynitrite-mediated oxidative stress. Excess production of peroxynitrite (PN) within the cellular medium can cause oxidative damage to biomolecules. The in vitro nitration of Ribonuclease A (RNase A) results in nitrotyrosine (NT) formation with a strong dependence on the pH of the medium. In order to mimic the cellular environment in this study, PN-mediated RNase A nitration has been carried out in a crowded medium. The degree of nitration is higher at pH 7.4 (physiological pH) compared to pH 6.0 (tumor cell pH). The extent of nitration increases significantly when PN is added to RNase A in the presence of crowding agents PEG 400 and PEG 6000. PEG has been found to stabilize PN over a prolonged period, thereby increasing the degree of nitration. NT formation in RNase A also results in a significant loss in enzymatic activity.

Circulating genotypes of Pneumocystis jirovecii and its clinical correlation in patients from a single tertiary center in India

The present study was carried out with the objectives of genotyping Pneumocystis jirovecii at three distinct loci, to identify the single nucleotide polymorphisms (SNPs), and to study its clinical implications in patients with Pneumocystis pneumonia (PCP). Analysis of genetic diversity in P. jirovecii from immunocompromised patients was carried out by genotyping at three distinct loci encoding mitochondrial large subunit rRNA (mtLSU rRNA), cytochrome b (CYB), and superoxide dismutase (SOD) using polymerase chain reaction (PCR) assays followed by direct DNA sequencing. Of the 300 patients enrolled in the present study, 31 (10.33%) were positive for PCP by a specific mtLSU rRNA nested PCR assay, whereas only 15 P. jirovecii could be amplified at the other two loci (SOD and CYB). These positives were further subjected to sequence typing. Important genotypic combinations between four SNPs (mt85, SOD110, SOD215, and CYB838) and clinical outcomes could be observed in the present study, and mt85A, mt85T, and SOD110C/SOD215T were frequently associated with "negative follow-up". These SNPs were also noted to be relatively more prevalent amongst circulating genotypes in our study population. The present study is the first of its kind from the Indian subcontinent and demonstrated that potential SNPs of P. jirovecii may possibly be attributed to the clinical outcome of PCP episodes in terms of severity or fatality in different susceptible populations likely to develop PCP during their course of illness.

Rapid identification of clinical mycobacterial isolates by protein profiling using matrix assisted laser desorption ionization-time of flight mass spectrometry

PURPOSE

The purpose of this study was to evaluate the identification of Mycobacterium tuberculosis which is often plagued with ambiguity. It is a time consuming process requiring 4-8 weeks after culture positivity, thereby delaying therapeutic intervention. For a successful treatment and disease management, timely diagnosis is imperative. We evaluated a rapid, proteomic based technique for identification of clinical mycobacterial isolates by protein profiling using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

MATERIALS AND METHODS

Freshly grown mycobacterial isolates were used. Acetonitrile/trifluoroacetic acid extraction procedure was carried out, following which cinnamic acid charged plates were subjected to identification by MALDI-TOF MS.

RESULTS

A comparative analysis of 42 clinical mycobacterial isolates using the MALDI-TOF MS and conventional techniques was carried out. Among these, 97.61% were found to corroborate with the standard methods at genus level and 85.36% were accurate till the species level. One out of 42 was not in accord with the conventional assays because MALDI-TOF MS established it as Mycobacterium tuberculosis (log (score)>2.0) and conventional methods established it to be non-tuberculous Mycobacterium.

CONCLUSIONS

MALDI-TOF MS was found to be an accurate, rapid, cost effective and robust system for identification of mycobacterial species. This innovative approach holds promise for early therapeutic intervention leading to better patient care.

Evaluation of retinal nerve fiber layer thickness parameters in myopic population using scanning laser polarimetry (GDxVCC)

INTRODUCTION

Myopia presents a significant challenge to the ophthalmologist as myopic discs are often large, tilted, with deep cups and have a thinner neuroretinal rim all of which may mimic glaucomatous optic nerve head changes causing an error in diagnosis.

OBJECTIVE

To evaluate the retinal fiber layer (RNFL) thickness in low, moderate and high myopia using scanning laser polarimetry with variable corneal compensation (GDxVCC).

SUBJECTS AND METHODS

One hundred eyes of 100 emmetropes, 30 eyes of low myopes (0 to - 4 D spherical equivalent(SE), 45 eyes with moderate myopia (- 4 to - 8D SE), and 30 eyes with high myopia (- 8 to - 15D SE) were subjected to retinal nerve fiber layer assessment using the scanning laser polarimetry (GDxVCC) in all subjects using the standard protocol. Subjects with IOP > 21 mm Hg, optic nerve head or visual field changes suggestive of glaucoma were excluded from the study. The major outcome parameters were temporal-superior-nasal-inferiortemporal (TSNIT) average, the superior and inferior average and the nerve fibre indicator (NFI).

RESULTS

The TSNIT average (p = 0.009), superior (p = 0.001) and inferior average (p = 0.008) were significantly lower; the NFI was higher (P less than 0.001) in moderate myopes as compared to that in emmetropes. In high myopia the RNFL showed supranormal values; the TSNIT average, superior and inferior average was significantly higher(p less than 0.001) as compared to that in emmetropes.

CONCLUSION

The RNFL measurements on scanning laser polarimetry are affected by the myopic refractive error. Moderate myopes show a significant thinning of the RNFL. In high myopia due to peripapillary chorioretinal atrophy and contribution of scleral birefringence, the RNFL values are abnormally high. These findings need to be taken into account while assessing and monitoring glaucoma damage in moderate to high myopes on GDxVCC.

Role of low dose mitomycin C in pterygium surgery

DOI: http://dx.doi.org/10.3126/nepjoph.v4i1.5881 NEPJOPH 2012; 4(1): 203-205

Evaluation of oxidative stress in pregnancy induced hypertension

This work was undertaken to investigate correlation between oxidative stress and initiation of pathogenesis of pregnancy induced hypertension (PIH). Fifty primigravidae in age group of 20-35 years and gestational age 28-42 weeks with PIH were taken as cases. Twenty healthy primigravidae with no medical and surgical complications of pregnancy and with blood pressure ≤140/90 mm Hg served as controls. The cases were again subgrouped as severe preeclampsia (12 in number) and mild pre-eclampsia (38 in number). All of them were evaluated for serum malondialdehyde (MDA), Serum vitamin E and plasma vitamin C levels. The serum MDA levels were raised significantly in women with mild preeclampsia (P<0.01) and in women with severe preeclampsia (P<0.01) in comparison to normal primi gravida. The serum vitamin E levels were decreased in primi gravida with mild preeclampsia (p<0.1) and in primi with severe pre eclampsia (P<0.1) in comparison to normal primi gravida but the fall was not statistically significant. There was a significant fall (P<0.05) in the vitamin C levels in primi with mild preeclampsia than in the normal primi. The vitamin C levels in severe preeclamptic patients were lower than the normal primi but the fall was not statistically significant (P=0.10). The serum MDA and vitamin E showed a negative correlation in all the cases. The serum MDA and plasma vitamin C also showed a negative correlation in the control and study group. This observation suggests that in hypertensive disorders of pregnancy there is an imbalance between lipid peroxidation and antioxidant vitamin status because of oxidative stress. The decreased serum concentrations of the antioxidant vitamins supports the hypothesis that lipid peroxidation is an important causative factor in the pathogenesis of preeclampsia. The rise in antioxidants is probably to compensate the increased peroxide load in severe preeclampsia.

Outcome of phacoemulsification in eyes with cataract and cornea opacity partially obscuring the pupillary area

OBJECTIVE

To evaluate the intra-operative difficulties and postoperative visual outcome following phacoemulisification and intraocular lens (IOL) implantation in eyes with cataract and a coexisting corneal opacity partially obscuring the pupillary area.

MATERIALS AND METHODS

The study included 205 eyes of 205 patients with cataract, an extensive corneal opacity partially obscuring the pupillary area and a corrected distance visual acuity (CDVA) of less than 40/200 who had undergone phacoemulisification with IOL implantation by a single surgeon. The patients were followed up on day 1, day 7, 1 month and 3 months postoperatively. Intra-operative and post operative course and CDVA were evaluated.

RESULTS

Seventy nine percent of the patients underwent phaco-emulsification via superior clear corneal approach while the rest were operated via temporal clear corneal approach. Trypan blue (0.06%) dye assisted capsulorrhexis was successfully completed in all eyes with additional maneuvers including posterior synechiolysis and sphincterotomy. Nucleotomy with primary chop technique and phacoemulsification were performed uneventfully in all but one eye, which was converted to an extra capsular cataract extraction (ECCE). A foldable intraocular lens was implanted in 76 eyes, rigid IOL in 128 eyes and 1 eye was left aphakic. The pre-operative CDVA of less than 40/200 improved to 20/60 at the end of 3 months follow up.

CONCLUSIONS

Phacoemulsification and intraocular lens implantation provides ambulatory and useful vision in eyes with coexisting cataract and corneal opacity.

Trypan blue staining of filtering bleb in eyes with operate trabeculectomy

OBJECTIVE

To report the use of trypan blue staining of the filtering bleb to assess its functional status in eyes undergoing phacoemulsification after trabeculectomy.

SUBJECTS AND METHODS

This retrospective study was conducted at a tertiary eye care centre in North India and studied 33 eyes of 33 patients ( with previously operated trabeculectomy), who underwent phacoemulsification. Trypan blue dye (0.06%) was used to stain the anterior capsule. After completion of phacoemulsification, the staining of the trabeculectomy bleb was noted as diffuse, patchy, minimal or no staining.

RESULTS

Of the 33 eyes, 13 had diffuse staining (39.4%, mean IOP = 9.3 ± 2.2 mm Hg), 7 (21.2%, mean IOP= 15.5 ± 1.8 mm Hg) had patchy staining, 4 had minimal staining (12.1%, mean IOP= 17.5 ± 0.5mm Hg) and nine (27.3%, mean IOP= 19.3 ± 1.6 mm Hg) had no staining. These staining patterns were labeled as groups 1 - 4 respectively. Statistical analysis showed that the difference between the IOPs in Group 1 - 2 and between Group 2 - 3 was not significant statistically (p=0.682 and 0.665 respectively). However the differences between the IOPs between Groups 1 - 3, 1 - 4, 2 - 4, and 3 - 4 were found to be highly significant statistically (p less than 0.0005).

CONCLUSIONS

Trypan blue dye can be used to test the amount of sub conjunctival filtration in eyes undergoing phacoemulsification cataract surgery.

Repositioning of Ahmed glaucoma valve tube in the anterior chamber with prolene sutures to manage tube-endothelial touch

Background: Corneal endothelial damage is a known complication of aqueous shunt surgery. Objective: To describe a new technique for repositioning the Ahmed glaucoma valve tube in a case of tube-endothelial touch.Case: A patient with advanced glaucoma, having undergone Ahmed glaucoma valve (AVG) implantation, developed localized corneal endothelial damage due to contact between the tube and superior corneal endothelium. Two 10-0 prolene anchor sutures were passed over the tube in the anterior chamber, repositioning it away from the endothelium, thus preventing further damage to the corneal endothelium. Resolution of corneal oedema was noted without affecting the tube drainage and intraocular pressure. Conclusion: Intracameral repositioning of the shunt tube using prolene sutures is a useful technique for correcting the tube malposition.DOI: http://dx.doi.org/10.3126/nepjoph.v4i2.6549 Nepal J Ophthalmol 2012; 4 (2): 309-411  

Ocular surface squamous neoplasia in a young adult - its nature and unusual course

BACKGROUND

We describe a case of a recurrent ocular surface squamous neoplasia (OSSN) in a 37-year-old male with a mass at the infero-temporal quadrant along with an isolated primary lesion at the upper nasal quadrant for the last five months with a past history of surgical excision 7 years ago for a nodular mass in the same eye. The mass showed delayed response to Mitomycin C (MMC) therapy and finally developed limbal stem cell deficiency.

CASE REPORT

A 37-year-old male presented with a five-month history of foreign body sensation and localized conjunctival hyperemia and two progressively enlarging bumps over the limbus in the left eye. The past history stated a surgical excision , done 7 years ago, for a nodular mass cytology. The patient received initial treatment with 0.02% MMC, but did not show any improvement even after 3 cycles, but later showed marked chemoreduction with 0.04% MMC on two cycles and a complete resolution of the neoplasia after two more cycles. Impression cytology at six months revealed no abnormality. But at the 10-month follow-up. limbal stem cell deficiency was observed.

CONCLUSION

While examining, managing and follow-up of a case of OSSN, one needs to know the atypical nature and response of the tumour. Long-term follow-up in these cases is mandatory.

Vascularized bone marrow-based immunosuppression inhibits rejection of vascularized composite allografts in nonhuman primates

Vascularized composite allograft (VCA) transplantation (also referred to as composite tissue allotransplantation) has demonstrated clinical success in cases of hand, arm and face transplantation despite prior belief that skin provides an insurmountable barrier to allograft rejection. These overall good outcomes are facilitated by substantial immunosuppressive requirements in otherwise healthy patients, yet still demonstrate frequent rejection episodes. We developed a nonhuman primate model of facial segment allotransplantation to elucidate the unique pathophysiology and immunosuppressive requirements of VCA with addition of concomitant vascularized bone marrow (VBM). Heterotopically transplanted facial segment VCA with VBM treated only with tacrolimus and mycophenolate mofetil (MMF) demonstrated prolonged rejection-free survival, compared to VCA without VBM that demonstrated early rejection episodes and graft loss. While VCA with VBM demonstrated sporadic macrochimerism, acute and chronic rejection and graft loss occurred after discontinuation of immunosuppression. These data support an immunomodulatory role of VBM in VCA that reduces immunosuppressive requirements while providing improved outcomes.

Safety of primary intraocular lens insertion in unilateral childhood traumatic cataract

This study analyzes the results of cataract surgery with primary intraocular lens implantation in unilateral childhood traumatic cataract following penetrating trauma and its long term follow up. It is a hospital based study of 114 children (age 3-10 years) with unilateral traumatic cataract who underwent extracapsular cataract extraction/ lens aspiration with implantation of posterior chamber intraocular lens (IOL). Primary posterior capsulotomy (PPC) was performed in 57 eyes and the rest 57 were without PPC (NPPC). The patients were followed up at regular intervals for a period of 3 years. Postoperative inflammation and pupillary capture were two frequent complications seen during postoperative period. Development of posterior capsular opacification (PCO) was 1/57, 4/57 at 8th week and 7/30 and 14/39 at 6 months, in PPC and NPPC group, respectively. Best corrected visual acuity (BCVA)>or=6/18 was achieved in 50% of eyes at 8th week post operatively and the same at 3 years with/without membranectomy/capsulotomy was evident in 73.3% of eyes. Meticulous case selection with insertion of "in the bag IOL" and subjecting the traumatized cataractous eyes to primary posterior capsulotomy are factors responsible for optimal outcome in unilateral traumatic cataract in children.

Safety of Primary Intraocular Lens Insertion in Unilateral Childhood Traumatic Cataract

This study analyzes the results of cataract surgery with primary intraocular lens implantation inunilateral childhood traumatic cataract following penetrating trauma and its long term follow up.It is a hospital based study of 114 children (age 3-10 years) with unilateral traumatic cataract whounderwent extracapsular cataract extraction/ lens aspiration with implantation of posterior chamberintraocular lens (IOL). Primary posterior capsulotomy (PPC) was performed in 57 eyes and the rest57 were without PPC (NPPC). The patients were followed up at regular intervals for a period of 3years.Postoperative inflammation and pupillary capture were two frequent complications seen duringpostoperative period. Development of posterior capsular opacification (PCO) was 1/57, 4/57 at 8thweek and 7/30 and 14/39 at 6 months, in PPC and NPPC group, respectively. Best corrected visualacuity (BCVA) ≥ 6/18 was achieved in 50% of eyes at 8th week post operatively and the same at 3years with/without membranectomy/capsulotomy was evident in 73.3% of eyes.Meticulous case selection with insersion of “in the bag IOL” and subjecting the traumatizedcataractous eyes to primary posterior capsulotomy are factors responsible for optimal outcome inunilateral traumatic cataract in children.Key words: childhood, intraocular lens, Nepal, traumatic cataract

Viscoexpression of large free floating Cysticercus cyst from the anterior chamber of the eye by double incision technique

We describe a case of 16-year-old girl who reported with diminution of vision in left eye for past seven months with appearance of white reflex. Slit lamp biomicroscopy revealed the presence of a live grayish white cyst in the anterior chamber. The ultrabiomicroscopic evaluation revealed a large live Cysticercus cellulosae cyst in anterior chamber. The CT-scan of the brain revealed multiple non-contrast enhanced lesions with calcification in brain parenchyma. The patient was started on oral prednisolone and oral albendazole. The cyst was removed in toto from the eye by double incision technique. The patient achieved visual acuity of 6/12 post-operatively.

Prevalence of glaucoma in Sunsari district of eastern Nepal

AIMS

To determine prevalence of glaucoma and glaucoma suspect in subjects 40 years and above in Sunsari district of eastern Nepal.

METHODS

A community based cross sectional study examining 1600 selected subjects was carried out. In all subjects best corrected visual acuity was determined. Oblique torch light test was used for anterior chamber depth evaluation. Intraocular pressure (IOP) measurements with Perkins tonometer and fundus examination were carried out in the community. Subjects diagnosed as glaucoma suspect were further evaluated in the hospital using slit lamp examination, gonioscopy and Goldmann perimetry. Glaucoma was defined by characteristic disc and visual field changes irrespective of the level of IOP.

RESULTS

Of 1600 subjects examined, the prevalence of glaucoma was found to be 0.938%. The prevalences of primary open angle glaucoma, primary angle closure glaucoma, secondary glaucoma and ocular hypertension were 0.562%, 0.125%, 0.250% and 0.500% respectively. Lens induced glaucoma accounted for all the cases of secondary glaucoma.

CONCLUSION

The prevalence of glaucoma in the Sunsari District of Nepal is 0.938%, which is lower than that reported in the neighboring regions. Lens induced glaucoma is highly prevalent as a cause of secondary glaucoma.

Striving for the perfect surgery in traumatic cataract following penetrating trauma in a tertiary care hospital at eastern Nepal

This study analyzes the result of traumatic cataract surgery in a tertiary care hospital at eastern Nepal. It is a hospital-based study of 112 patients (age 15-62), who underwent cataract extraction for unilateral traumatic cataracts. The study was carried out to evaluate the surgical outcome of tramatic cataract. Thirty-eight eyes had associated posterior capsular defect. No serious postoperative complications were encountered. Posterior capsular opacification at the end of sixth week was evident only in two eyes. Best corrected visual acuity nof 6/18 or more at the eighth week was achieved in 61 (54%) eyes. Astigmatism of less than 3D was achieved in 82 (73%) eyes. Rational surgical approach in traumatic cataract provides encouraging results. To comment on actual outcome long term follow up is mandatory.

Differential gene expression of sulindac-treated human breast epithelial cells

Breast cancer is the most common malignancy and the second major cause of cancer-related deaths among women in the United States. Recent advances in the molecular genetics of breast cancer have identified various genes associated with tumorigenesis. There is evidence that non-steroidal anti-inflammatory drugs, e.g. sulindac, have some anti-proliferative effects on various tumors involving altered p53 function. Most of these studies have been performed with various human colon carcinoma cell lines and few of them focus on non-malignant proliferative human mammary epithelial cell lines. Therefore, the present study was undertaken to analyze the differentially expressed genes of the p53 signaling pathway by means of a gene array for the immortalized human breast epithelial cell line, MCF-10F, treated with sulindac. Out of the total 96 genes, only 17 were altered by the drug treatment. Among these 17 genes, 6 showed significant alteration (Q > 2.0), whereas 11 genes showed moderate alterations. Altered genes included BRCA1 associated protein-1 [ubiquitin carboxy-terminal hydrolase (bap1)]; cell division cycle 2, G1 to S and G2 to M [cdk1(cdc2)]; and DNA-damage-inducible transcript 1 (gadd45), which were down-regulated. However, N-myc gene 1 (rtp), promyelocytic leukemia (pml), and nuclear factor of kappa-light polypeptide gene enhancer in B-cell 3 and p65 [avian (rel A)] were up-regulated. Northern blot analysis confirmed some of these alterations. The alteration of p53 signaling pathway gene markers by sulindac treatment can give us valuable information about the response to drug treatments in a proliferative cell population.

Pattern of intraocular pressure changes following manual small incision cataract surgery

OBJECTIVES

To find out the pattern of changes in intraocular pressure after manual small incision cataract surgery.

METHODS

Consecutive patients (291 eyes of 291 patients) undergoing manual small incision cataract surgery were prospectively evaluated for change in IOP. Patients were further divided into two groups based on whether or not sutures were used to close the scleral tunnel. IOP was serially measured at day 1, 1st, 2nd, 4th, 6th, 8th and 12th week.

RESULTS

The mean post operative IOP in eyes where sutures were not applied (12.59+/- 3.02 mmHg, 12.59+/-2.34mmHg, 12.54+/-2.19mmHg and 12.40+/-2.99 mm Hg at day1, 2week and 4weeks respectively) was lower than that where sutures were used to close the wound (15.57+/- 3.86mmHg, 14.05+/-2.52mmHg, 14.43+/-3.39mmHg at day1, 2weeks and 4 weeks respectively). There was a drop of IOP from the preoperative IOP in both suture (1.15+/-3.29mm Hg) and non suture (3.29+/-3.07mm Hg) group at 3 months of follow up.

CONCLUSION

There is a small drop of IOP following sutureless MSICS during long term follow up. Eyes where sutures are applied are more likely to have higher IOP than those without sutures at the initial post operative period.

Survival of Pseudomonas aeruginosa in M-K preserved corneas

AIM

To present seven eyes of suspected donor to host transmitted Pseudomonas sp corneal graft infection after corneal and scleral graft leading to corneal melting within 24 hours, in a span of 10 months.

METHODS

Case series. Seven eyes, operated for either penetrating or lamellar keratoplasty or scleral patch graft for different indications and which developed massive corneal/corneoscleral infection within 24 hours, were studied prospectively.

RESULTS

Pseudomonas aeruginosa, resistant to almost all antibiotics except polymyxin B in all and vancomycin in two, was identified as the causative organism from all the specimens obtained from the infected graft.

CONCLUSION

Post-keratoplasty infection is a disaster. The source of early infection is invariably iatrogenic. Use of empirical antibiotics in the media is not always sufficient to prevent such infection. Thus, measures must be taken in the form of strict maintenance of asepsis and revision of antibiotics added to the storage medium. Further, early recognition and energetic therapy for such infection could reduce the ophthalmic morbidity.

Laboratory diagnosis in ulcerative keratitis

AIMS

To identify the common bacterial and fungal isolates from corneal ulcers and to determine the antimicrobial susceptibility patterns of bacterial isolates to commonly used antibiotics at B.P. Koirala Institute of Health Sciences (BPKIHS), eastern Nepal. Culture and direct microscopic correlation and reliability were also compared.

METHODS

All patients with suspected corneal ulceration presenting to the Ophthalmology Department of BPKIHS from 1st August 1998 to 31st July 2001 were evaluated. Corneal scraping was performed and processed for direct microscopy and culture for bacterial and fungal isolates. Bacterial isolates were subjected to antimicrobial susceptibility testing.

RESULTS

Of 447 specimens examined direct microscopy was positive in 216 (48%) specimens. Culture positivity could be correlated with direct microscopy in 179 (83%) of specimens. Growth of etiologic agents was found in 303 (67.8%) samples. Of these 145 (47.8%) had pure fungal growth, 103 (34%) had pure bacterial growth and 55 (18.2%) had mixed fungal and bacterial infection. The commonest fungal pathogen was Aspergillus spp.in 78 (38.4%) followed by Fusarium spp. in 45 (22%). Aureobasidium sp. was isolated in 25 (12.3%) samples. Staphylococcus aureus (93, 56.7%) dominated the scene as the commonest bacterial agent. Streptococcus pneumoniae (33, 20%) was second in the list. Most of the bacterial isolates were sensitive to commonly used antibiotics.

CONCLUSION

This study emphasizes the importance and need of the continued surveillance of the agents and their antimicrobial susceptibility for the prevention and management of corneal ulcers and their complications.

Evaluating role of oxidative stress in determining the pathogenesis of falciparum malaria induced acute renal failure

Serum malondialdehyde was measured in sixty-one falciparum malaria cases, which include thirty uncomplicated, and thirty-one complicated with acute renal failure. Twenty-six healthy individuals were also studied as controls. Serum malondialdehyde level was found to be significantly elevated in falciparum malaria induced acute renal failure cases when compared with uncomplicated falciparum malaria (p<0.001) and healthy controls (p<0.001). A positive correlation with the raised urea, creatinine and bilirubin levels were significant (r=0.62, p<0.025; r=0.65, p<0.05 and r=0.72, p<0.001 respectively) indicating the severity of complication with rise of lipid peroxides in falciparum malaria induced acute renal failure cases.

Recombinant Newcastle disease virus as a vaccine vector

Veterinary vaccines remained conventional for more than fifty years. Recent advances in the recombinant genetic engineering techniques brought forward a leap in designing vaccines for veterinary use. A novel approach of delivering protective immunogens of many different pathogens in a single virus vector was made possible with the introduction of a "reverse genetics" system for nonsegmented negative-sense RNA viruses. Newcastle disease virus (NDV), a nonsegmented negative-sense virus, is one of the major viruses of economic importance in the poultry industry throughout the world. Despite the availability of live virus vaccines of good potency, the intrinsic ability of attenuated strains to revert in virulence makes control of this disease by vaccination difficult. Armed with the knowledge of virulence factors of this virus, it is now possible to produce genetically stable vaccines and to engineer mutations that enhance immunogenicity. The modular nature of the genome of this virus facilitates engineering additional genes from several different pathogens or tumor-specific antigens to design contemporary vaccines for animals and humans. This review will summarize the developments in using NDV as a vaccine vector and the potential of this approach in designing next generation vaccines for veterinary use.

CT in the diagnosis of isolated cysticercal infestation of extraocular muscle

AIM

To evaluate the use of computed tomography (CT) and ultrasound (US) to diagnose orbital cysticercosis, and present the diagnostic features.

METHOD

US and CT were used to evaluate patients with proptosis. Four patients were diagnosed as having orbital myocysticercosis and treated with oral albendazole and corticosteroid. Follow-up was undertaken with US and CT.

RESULT

US features were confirmatory of myocysticercosis in two eyes where as CT was effective in diagnosing the condition in all four eyes. In two patients the medial rectus was involved, in one the superior rectus and, in the other, the inferior rectus muscles. Serial US and CT revealed complete resolution of the lesions in 3 months.

CONCLUSION

CT is useful method in diagnosing isolated orbital myocysticercosis. Our report demonstrated that ophthalmic signs and symptoms in the presence of proptosis, especially in an endemic region, should alert the clinician to the possibility of myocysticercosis. Though CT is superior, US can be used as a economical follow-up investigation.