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.