Evaluation of the Recombinant Bacterial Chitinases as Anti-proliferative and Anti-migratory Agents for the Human Breast Cancer Cell Line, MCF-7

Chitinases, a glycosyl hydrolase family 18 members, have a wide distribution in both prokaryotes and eukaryotes, including humans. Regardless of the absence of endogenous chitin polymer, various chitinases and chitinase-like proteins (CLPs) have been reported in mammals. However, several other carbohydrate polymers, such as hyaluronic acid and heparan sulfate, show structural similarities with chitin, which could be a potential target of chitinase and CLPs. Heparan sulfate is part of the integral membrane proteins and involves in cell adherence and migration. Hence, to demonstrate the effect of chitinase on cancer cell progression, we selected two chitinases from Serratia marcescens, ChiB and ChiC, which function as exo- and endo-chitinase, respectively. The ChiB and ChiC proteins were produced recombinantly by cloning chiB and chiC genes from Serratia marcescens. The cell viability of the Michigan Cancer Foundation-7 (MCF-7) cells was studied using different concentrations of the purified recombinant proteins. Cell viability assay was performed using 3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide and water-soluble tetrazolium salt, and the effect of ChiB and ChiC on cell proliferation was studied by clonogenic assay. The cell migration study was analysed by wound healing, transwell migration, and invasion assays. Cell cycle analysis of propidium iodide-stained cells and cell proliferation markers such as pERK1/2, pAKT, and SMP30 were also done. It was observed that both ChiB and ChiC were able to impede cell viability, cell migration, and invasion significantly. These observations and our in silico molecular docking analysis suggest that ChiC is a potential anticancer agent and is more efficient than ChiB. Since the ChiC is able to inhibit both cancer cell proliferation and migration, it could be a potential candidate for the treatment of metastatic cancer.

Anti-biofilm potential of human senescence marker protein 30 against Mycobacterium smegmatis

Human senescence marker protein 30 (huSMP30) has been characterized as a multifaceted protein consisting of various enzymatic and cellular functions. It catalyzes the interconversion of L-gulonate and L-gulono-γ-lactone in the ascorbate biosynthesis pathway. Therefore, we hypothesized that it could be a potential anti-biofilm agent against pathogenic bacteria due to its lactonase activity. In order to corroborate this, the huSMP30 was recombinantly expressed, purified, and analyzed for its ability to inhibit Mycobacterium smegmatis biofilm formation, which showed a concentration-dependent inhibition as compared to the untreated control group. Further, in silico analysis was performed to redesign the huSMP30 with enhanced lactonase activity. Molecular docking analysis of the huSMP30 and lactone substrates facilitated the selection of three single amino acid substitutions (E18H, N154Q, and D204V), which were created using a PCR-based site-directed mutagenesis reaction. These mutant proteins and the wild-type huSMP30 were purified, and the effects on the enzymatic activity and biofilm formation were studied. The mutants E18H and D204V showed non-significant effects on specific lactonase activity, catalytic efficiency, and anti-biofilm property; however, the mutant N154Q showed significant improvement in the specific lactonase activity, catalytic efficiency, and inhibition in the biofilm formation. The protein stability analysis revealed that the wild-type huSMP30 and its designed mutants were stable at 37 °C for up to 4 days. In conclusion, the anti-biofilm property of the huSMP30 has been established, and an engineered version, N154Q, inhibits biofilm formation with greater efficiency. Human SMP30 is a versatile protein with multiple cellular and enzymatic functions, however, its anti-biofilm potential has not been explored. Our work presents the method to produce soluble and active huSMP30 in the E. coli expression system and establishes its role as an anti-biofilm agent against Mycobacterium smegmatis owing to its lactonase activity. Our results provide support for the future advancement of huSMP30 as a potential anti-biofilm agent targeting pathogenic Mycobacterium species.

Heterogeneity of management practices surrounding operable gallbladder cancer - results of the OMEGA-S international HPB surgical survey

BACKGROUND

Gallbladder cancer (GBC) is an aggressive, uncommon malignancy, with variation in operative approaches adopted across centres and few large-scale studies to guide practice. We aimed to identify the extent of heterogeneity in GBC internationally to better inform the need for future multicentre studies.

METHODS

A 34-question online survey was disseminated to members of the European-African Hepatopancreatobiliary Association (EAHPBA), American Hepatopancreatobiliary Association (AHPBA) and Asia-Pacific Hepatopancreatobiliary Association (A-PHPBA) regarding practices around diagnostic workup, operative approach, utilization of neoadjuvant and adjuvant therapies and surveillance strategies.

RESULTS

Two hundred and three surgeons responded from 51 countries. High liver resection volume units (>50 resections/year) organised HPB multidisciplinary team discussion of GBCs more commonly than those with low volumes (p < 0.0001). Management practices exhibited areas of heterogeneity, particularly around operative extent. Contrary to consensus guidelines, anatomical liver resections were favoured over non-anatomical resections for T3 tumours and above, lymphadenectomy extent was lower than recommended, and a minority of respondents still routinely excised the common bile duct or port sites.

CONCLUSION

Our findings suggest some similarities in the management of GBC internationally, but also specific areas of practice which differed from published guidelines. Transcontinental collaborative studies on GBC are necessary to establish evidence-based practice to minimise variation and optimise outcomes.

Rate of Falls, Fear of Falling, and Avoidance of Activities At-Risk for Falls in Older Adults With Glaucoma

PURPOSE

To determine the relationship between glaucoma severity and rate of falls, fear of falling, and avoidance of activities at-risk for falls.

DESIGN

Cross-sectional study.

METHODS

Patients with glaucoma (n = 138) 55 to 90 years of age with mild (n = 61), moderate (n = 54), or advanced (n = 23) glaucoma in the better eye based on the Glaucoma Staging System and age-matched control subjects (n = 50) were recruited from the Eye Clinics at Washington University, St. Louis, MO. Participants completed questionnaires regarding falls, the fear of falling, and the avoidance of activities at-risk for falls.

RESULTS

Of the glaucoma participants, 36% reported ≥1 fall in the previous 12 months compared with 20% of control subjects (adjusted odds ratio [OR] 2.7 [95% confidence interval {CI} 1.18-6.17]; P = .018). Compared with control subjects, the mild glaucoma group trended toward a higher fall risk (adjusted OR 2.43 [95% CI 0.97-6.08]; P = .059) and the advanced group had the highest fall risk (adjusted OR 7.97 [95% CI 2.44-26.07]; P = .001). A greater risk of a high fear of falling and high avoidance of at-risk activities occurred at the moderate stage of glaucoma compared with control subjects (adjusted OR 4.66 [95% CI 1.24-17.49]; P = .023 and adjusted OR 4.49 [95% CI 1.34-15.05]; P = .015, respectively).

CONCLUSIONS

Patient education, interventions, and appropriate referrals to minimize falls should be considered in older adults with early glaucoma and continue with advancing disease. Minimizing a patient's fall risk may decrease their fear of falling and avoidance of at-risk activities. Reducing falls, the fear of falling, and the avoidance of at-risk activities may lower morbidity and mortality and improve emotional and social well-being of patients with glaucoma. Am J Ophthalmol 2021;221:•••-•••. © 2021 Elsevier Inc. All rights reserved.

THU0540 A PHASE 2B STUDY OF INTRAVENOUSLY (IV) ADMINISTERED TC 99M TILMANOCEPT TO DETERMINE DIFFERENTIAL UPTAKE, REPRODUCIBILITY OVER TIME AND IMAGE STABILITY IN HEALTHY SUBJECTS AND IN PATIENTS WITH RHEUMATOID ARTHRITIS (RA) ON STABLE TREATMENT

Background:

At present, there are no reliable noninvasive means to directly monitor disease activity in RA patients. Activated macrophages are a critical component of the inflammatory etiology of RA due to their role in prolonged RA joint inflammation and destruction through the release of pro-inflammatory cytokines and chemokines. Tc 99m tilmanocept is a radiopharmaceutical imaging agent that binds with high affinity to the macrophage mannose receptor CD206 that resides on activated macrophages. Previous clinical trials demonstrated safety and tolerability of Tc 99m tilmanocept, as well as a determination of optimal clinical dose and timeframe for RA imaging.

Objectives:

The current phase 2b study aims to evaluate reproducibility and stability of imaging and will assess quantitative Tc 99m tilmanocept uptake cut points that reliably enable discrimination between joints of healthy people and RA patients.

Methods:

The analysis cohort contained 18 healthy controls (HC) clinically free of inflammatory joint disease and 12 subjects with clinically diagnosed RA who are on stable anti-inflammatory and/or anti-rheumatic therapy. Each subject received a 150-mcg dose of tilmanocept radiolabeled with 10 mCi of Tc 99m in a 3mL IV injection. Injection was followed by planar imaging at 60 and 180 minutes for both HC and RA subjects on study Day 0 and repeated in RA subjects on Day 8. Images were quantitatively assessed to detect localization within synovial spaces of bilateral hands and wrists by determining average pixel intensity in each region of interest relative to average pixel intensity in a joint-specific reference region.

Results:

Data obtained from the interim analysis support the hypothesis that Tc 99m tilmanocept imaging can provide robust quantitative imaging in HC and RA subjects. Repeat images within and between days demonstrate root mean squared differences that are approximately 10% or less of the observed localization of Tc 99m tilmanocept. Qualitatively, images of HC indicated no disease-related site-specific localization, whereas localization is present in RA subjects at levels expected given the difference in macrophage number and density in different pathotypes of RA. Notably, images from patients with active RA exhibit the same localization patterns on images taken in a test-retest fashion on the same day as well as in subjects with images acquired on Day 0 and Day 8 (see Figure 1). These results show low imaging readout variability, enabling reliable quantification of joints with RA-involved macrophage-mediated inflammation. Analysis of the HC and RA images was used to determine initial quantitative “cut-points” to differentiate between joints with and without the inflammation typically seen in RA.

Figure 1.

Tilmanocept consistently localizes in areas of macrophage-driven inflammation, demonstrating low variability. RA patients exhibit reproducible localization over a 1-week period. Typical of healthy subjects, no evidence of inflammation-related Tc 99m tilmanocept uptake was observed in the healthy control. Images on the right show same patient imaged on 2 different days.

Conclusion:

Tc 99m tilmanocept imaging of the joints in healthy subjects as well as in patients with active RA under stable treatment is reproducible and stable over time. The results confirmed that the signal in joints of healthy subjects and RA patients can be quantified and used to establish cut points to distinguish inflamed and non-inflamed joints on a joint-by-joint basis. These results provide the foundation for a noninvasive, objective method to monitor activity in macrophage-driven inflammation in joints of patients with RA.

Disclosure of Interests:

Ayah Hussein Employee of: Currently employed by Navidea Biopharmaceuticals, David Ralph Consultant of: Previous consultant for Navidea Biopharmaceuticals, Employee of: Currently employed by Navidea Biopharmaceuticals, Beth Potter Employee of: Currently employed by Navidea Biopharmaceuticals, Bonnie Abbruzzese Employee of: Currently employed by Navidea Biopharmaceuticals, Rachael Hershey Employee of: Currently employed by Navidea Biopharmaceuticals, Katherine Repp Employee of: Previously employed by Navidea Biopharmaceuticals, Haya Shakhtra Employee of: Currently employed by Navidea Biopharmaceuticals, Mehak Goel Employee of: Currently employed by Navidea Biopharmaceuticals, Madison Palmer Employee of: Currently employed by Navidea Biopharmaceuticals, Allison Kissling Employee of: Previously employed by Navidea Biopharmaceuticals, Carley Hartings Employee of: Previously employed by Navidea Biopharmaceuticals, Michael Blue Employee of: Currently employed by Navidea Biopharmaceuticals, Michael Rosol Employee of: Currently employed by Navidea Biopharmaceuticals

Robotic resections in hepatobiliary oncology - initial experience with Xi da Vinci system in India

INTRODUCTION

Minimal invasive surgery has proven its advantages over open surgeries in the perioperative period. Food and Drug Administration approved da Vinci robot in 2000. The latest version, da Vinci Xi system has a mobile tower-based robot with several modifications to improve the functionality, versatility, and operative ease. None of the centers have reported exclusively on hepatobiliary oncology using the da Vinci Xi system. We report our initial experience.

AIMS AND OBJECTIVES

To study the feasibility, advantages, and discuss the operative technique of da Vinci Xi system in hepatobiliary oncology.

MATERIALS AND METHODS

Data were analyzed retrospectively from a prospectively maintained database from June 2015 to October 2016. Twenty-five patients with suspected or proven hepatobiliary malignancies were operated. Total robotic technique using da Vinci Xi system was used. Demographic details and perioperative outcomes were noted.

RESULTS

Of the 25 surgeries, 14 patients had a suspected gallbladder malignancy, 11 patients had primary or metastatic liver tumor. Median age was 53 years. The average duration of surgery was 225 min with a median blood loss 150 ml. The median postoperative stay was 4 days. The median nodal yield for radical cholecystectomy was seven. Five patients required conversion. Two of these developed postoperative morbidity.

CONCLUSION

Robotic surgery for hepatobiliary oncology is feasible and can be performed safely in experienced hands. Increasing experience in this field may equal or even prove advantageous over conventional or laparoscopic approach in future. A cautious approach with judicious patient selection is the key to establishing robotic surgery as a standard surgical approach.

Evaluation of two internal fixation techniques for mandibular parasymphyseal fractures comparing conventional titanium miniplates with customised titanium CRB omega miniplates: a prospective study

Our aim was to compare the efficacy and outcome of customised, titanium, CRB (Chandrashekhar Rushiji Bande), omega miniplates with those of conventional titanium miniplates in the management of parasymphyseal fractures of the mandible, with or without involvement of the mental nerve, after clinical and radiographic evaluation. A total of 252 parasymphyseal fractures in 200 patients were selected for the study over the period of seven years (January 2010-January2017) and divided randomly into two groups. The first group included 126 fractures treated with two conventional titanium miniplates (conventional group) and the second 126 fractures treated with one customised, titanium, CRB, omega miniplate (customised group). All operations were done by the same surgeon. Duration of operation (from placement of incision to closure of the defect) was recorded. Postoperative paraesthesia, infection, and acceptability of the plate to patients were also recorded. Postoperative healing was evaluated radiologically at one week and six months postoperatively. Operations were significantly shorter, and significantly fewer patients developed paraesthesia or infection, in the customised group. These patients were also happier with their miniplates, and had good radiological bony healing. In conclusion, a single customised, titanium, CRB, omega miniplate is an effective and economical alternative to two conventional titanium miniplates in the management of parasymphysis fractures of the mandible.

Regenerative endodontic treatment of an immature tooth with a necrotic pulp and apical periodontitis using platelet-rich plasma (PRP) and mineral trioxide aggregate (MTA): a case report

AIM

To report the successful clinical and radiographic outcome of a regenerative endodontic treatment.

SUMMARY

A 16-year-old male patient presented with a discoloured, maxillary left lateral incisor with a necrotic pulp. Radiographic examination revealed an incompletely developed root with an open apex. Under local anaesthesia and rubber dam isolation, an access cavity was prepared and the necrotic pulpal remnants were removed. The canal was disinfected without mechanical instrumentation with 5.25% NaOCl solution and dried with sterile paper points. A triple antibiotic (metronidazole, ciprofloxacin and minocycline) mixed with distilled water was packed in the canal and left for 28 days. Ten millimetres of whole blood was drawn by venipuncture from the patients antecubital vein for preparation of platelet-rich plasma (PRP). After removal of the antibiotic mixture, the PRP was injected into the canal space up to the cementoenamel junction level. Three millimetres of white MTA was placed directly over the PRP clot. Two days later, the tooth was restored with permanent filling materials. The patient was recalled for 3, 6, 12, 24 and 36 months clinical/radiographic follow-up. A 3-year follow-up radiograph revealed resolution of the periapical lesion, increased thickening of the root walls, further root development and continued apical closure of the root apex. The tooth was not responsive to cold tests; however, sensitivity tests with an electric pulp tester (EPT) elicited a delayed positive response.

KEY LEARNING POINTS

Regeneration is a viable treatment modality that allows continued root development of immature teeth with open apices and necrotic pulps. Platelet-rich plasma appears to be a suitable scaffold for regeneration of vital tissues in teeth with a necrotic pulps and an associated periapical lesion. Regenerative endodontic procedures may offer an effective treatment option to save teeth with compromised structural integrity.

Cochlin, intraocular pressure regulation and mechanosensing

Fluid shear modulates many biological properties. How shear mechanosensing occurs in the extracellular matrix (ECM) and is transduced into cytoskeletal change remains unknown. Cochlin is an ECM protein of unknown function. Our investigation using a comprehensive spectrum of cutting-edge techniques has resulted in following major findings: (1) over-expression and down-regulation of cochlin increase and decrease intraocular pressure (IOP), respectively. The overexpression was achieved in DBA/2J-Gpnmb⁺/SjJ using lentiviral vectors, down-regulation was achieved in glaucomatous DBA/2J mice using targeted disruption (cochlin-null mice) and also using lentiviral vector mediated shRNA against cochlin coding region; (2) reintroduction of cochlin in cochlin-null mice increases IOP; (3) injection of exogenous cochlin also increased IOP; (4) increasing perfusion rates increased cochlin multimerization, which reduced the rate of cochlin proteolysis by trypsin and proteinase K; The cochlin multimerization in response to shear stress suggests its potential mechanosensing. Taken together with previous studies, we show cochlin is involved in regulation of intraocular pressure in DBA/2J potentially through mechanosensing of the shear stress.

Cochlin induced TREK-1 co-expression and annexin A2 secretion: role in trabecular meshwork cell elongation and motility

Fluid flow through large interstitial spaces is sensed at the cellular level, and mechanistic responses to flow changes enables expansion or contraction of the cells modulating the surrounding area and brings about changes in fluid flow. In the anterior eye chamber, aqueous humor, a clear fluid, flows through trabecular meshwork (TM), a filter like region. Cochlin, a secreted protein in the extracellular matrix, was identified in the TM of glaucomatous patients but not controls by mass spectrometry. Cochlin undergoes shear induced multimerization and plays a role in mechanosensing of fluid shear. Cytoskeletal changes in response to mechanosensing in the ECM by cochlin will necessitate transduction of mechanosensing. TREK-1, a stretch activated outward rectifying potassium channel protein known to act as mechanotransducer was found to be expressed in TM. Cochlin expression results in co-expression of TREK-1 and filopodia formation. Prolonged cochlin expression results in expression and subsequent secretion of annexin A2, a protein known to play a role in cytoskeletal remodeling. Cochlin interacts with TREK-1 and annexin A2. Cochlin-TREK-1 interaction has functional consequences and results in changes in cell shape and motility. Annexin A2 expression and secretion follows cochlin-TREK-1 syn-expression and correlates with cell elongation. Thus cytoskeleton changes in response to fluid shear sensed by cochlin are further mediated by TREK-1 and annexin A2.

Pandemic influenza A (H1N1) 2009 vaccine: an update

The world witnessed a the first influenza pandemic in this century and fourth overall since first flu pandemic was reported during the World War I. The past experiences with influenza viruses and this pandemic of H1N1 place a consider-able strain on health services and resulted in serious illnesses and a large number of deaths. Develop-ing countries were declared more likely to be at risk from the pandemic effects, as they faced the dual problem of highly vulnerable populations and limited resources to respond H1N1. The public health experts agreed that vaccination is the most effective ways to mitigate the negative effects of the pandemic. The vaccines for H1N1 virus have been used in over 40 countries and administered to over 200 million people helped in a great way and on August 10, 2010, World Health Organization (WHO) announced H1N1 to be in postpandemic period. But based on knowledge about past pandemics, the H1N1 (2009) virus is expected to continue to circulate as a seasonal virus and may undergo some agenic-variation. As WHO strongly recommends vaccination, vigilance for regular updating of the composition of influenza vaccines, based on an assessment of the future impact of circulating viruses along with safety surveillance of the vaccines is necessary. This review has been done to take a stock of the currently available H1N1 vaccines and their possible use as public health intervention in the postpandemic period.

Underlying prothrombotic states in pregnancy associated cerebral venous thrombosis

BACKGROUND

The exact pathogenesis of pregnancy associated cerebral venous thrombois is still unsettled. Aims : To identify possible inherited and acquired prothrombotic risk factors and also identify the factors associated with mortality in pregnancy associated CVT.

SETTINGS AND DESIGN

Prospective cohort study to identify prothrombotic risk factors and case control study of influence of local traditional practice of puerperal water restriction on postpartum CVT.

MATERIALS AND METHODS

Consecutive patients with pregnancy associated CVT seen over a period of three years. Thrombotic workup included genetic markers, protein assays, and other factors.

STATISTICAL ANALYSIS

Univariate and chi-square analysis.

RESULTS

Of the 41 patients studied during the study period, 71% of patient had a single and 34% had multiple prothrombotic risk factors. Methylene tetrahydro-folate reductase (MTHFR) heterozygosity (19.5%) and factor V Leiden heterozygous (7.3%) were the commonest genetic markers. Hyperhomocysteinemia (34%) and elevated factor VIII levels (14.6%) were the other important risk factors. In this cohort the mortality was 17%. Mortality increased by odds of 1.3 for every additional prothrombotic marker. The factors associated with increased mortality included: status epileptics (P = 0.05, OR 13.2, 95% CI 1.002 - 173), deep venous system involvement (P = 0.016, OR 9.64, 95% CI 1.53 - 60.6), presence of midline shift (P = 0.012, OR 24.7, 95% CI 2.05 - 29.8) and diffuse cerebral edema (P = 0.006, OR 14.5, 95% CI 2.18- 96.4). The traditional practice of decrease intake of water during puerperium was significant in woman with pregnancy associated CVT when compared to control subjects (P < 0.02).

CONCLUSION

In patients with pregnancy associated CVT, prothrombotic markers can be multiple and are associated with increased odds of mortality. Deep venous system involvement, presence of midline shift and diffuse cerebral edema increased mortality. Peuperial water restriction may be a modifiable risk factor.

Aqueous humor dynamics: a review

Glaucoma is a family of optic neuropathies which cause irreversible but potentially preventable vision loss. Vision loss in most forms of glaucoma is related to elevated IOP with subsequent injury to the optic nerve. Secretion of aqueous humor and regulation of its outflow are physiologically important processes for maintaining IOP in the normal range. Thus, understanding the complex mechanisms that regulate aqueous humor circulation is essential for management of glaucoma. The two main structures related to aqueous humor dynamics are the ciliary body and the trabecular meshwork (TM). Three mechanisms are involved in aqueous humor formation: diffusion, ultrafiltration and active secretion. Active secretion is the major contributor to aqueous humor formation. The aqueous humor flow in humans follows a circadian rhythm, being higher in the morning than at night. The aqueous humor leaves the eye by passive flow via two pathways - the trabecular meshwork and the uveoscleral pathway. In humans, 75% of the resistance to aqueous humor outflow is localized within the TM with the juxtacanalicular portion of the TM being the main site of outflow resistance. Glycosaminoglycan deposition in the TM extracellular matrix (ECM) has been suggested to be responsible for increased outflow resistance at this specific site whereas others have suggested deposition of proteins, such as cochlin, obstruct the aqueous humor outflow through the TM. The uveoscleral outflow pathway is relatively independent of the intraocular pressure and the proportion of aqueous humor exiting the eye via the uveoscleral pathway decreases with age.

Decreased carbohydrate metabolism enzyme activities in the glaucomatous trabecular meshwork

PURPOSE

To determine whether activity of carbohydrate metabolism enzymes (aldolase, pyruvate kinase, isocitrate dehydrogenase, and malate dehydrogenase) are altered in the glaucomatous trabecular meshwork (TM) compared to controls.

METHODS

Tissue specimens were obtained from trabeculectomy (n=45 open angle glaucoma; Caucasian, average age 61+/-8 years of age of both genders) and from cadaver eyes (n=15 control and n=5 glaucoma; Caucasian, average age 63+/-4 years of both genders). Protein extracts from TM tissue were prepared in a non-denaturing buffer containing 0.1% genapol. Aldolase activity was measured spectrophotometrically at 240 nm absorbance using reaction of 3-phosphoglycerate with hydrazine to form hydrazone. Pyruvate kinase activity was measured by coupling lactate dehydrogenase with NADPH and pyruvate absorbance was measured at 340 nm. Isocitrate dehydrogenase activity was measured using reduction of NADP to NADPH at the characteristic absorbance at 340 nm. Malate dehydrogenase catalyzes the interconversion of L-malate and oxaloacetate using NADP as a coenzyme, quantified by its absorbance at 340 nm.

RESULTS

Aldolase, pyruvate kinase, isocitrate dehydrogenase, and malate dehyrogenase activities in the glaucomatous TM tissue were found to be reduced 70, 50, 25, and 69 percent, respectively. SDS-PAGE analysis suggests the presence of 4-hydorxynonenal (HNE) modified isocitrate dehydrogenase protein in the glaucomatous TM tissue compared to controls.

CONCLUSIONS

Several Krebs cycle enzyme activities are considerably reduced in glaucomatous TM. HNE modified isocitrate dehydrogenase activity is consistent with reduced inactivated form of the protein. Lipid peroxidation product modification of aldolase, pyruvate kinase, and isocitrate dehydrogenase serves as a likely reason for the reduction of enzyme activity.

Evaluation of intrastromal injection of voriconazole as a therapeutic adjunctive for the management of deep recalcitrant fungal keratitis

PURPOSE

To evaluate the role of intrastromal injection of voriconazole in the management of deep recalcitrant fungal keratitis.

DESIGN

Interventional case series.

METHODS

SETTING

Cornea services at a tertiary care teaching hospital.

PATIENTS

Three eyes of three patients with deep stromal recalcitrant fungal keratitis not responding to topical antifungal medications. Intervention Procedure: Voriconazole 50 micrograms/0.1 ml was injected circumferentially around the fungal abscess in the corneal stroma as an adjunctive to the topical antifungal therapy.

MAIN OUTCOME MEASURE

Main outcome measure was a reduction in size of the abscess and resolution of the infection.

RESULTS

Before the intracorneal injection, all three eyes had gradually worsening lesions on topical medications. After the intervention, a faster reduction in the size of corneal infiltration was documented and a complete resolution of the ulcers was seen within three weeks in all cases.

CONCLUSION

Targeted delivery of voriconazole by intracorneal injection may be a safe and effective way to treat cases of deep-seated recalcitrant fungal keratitis responding poorly to conventional treatment modalities.

Porphyrin binding to jacalin is facilitated by the inherent plasticity of the carbohydrate-binding site: novel mode of lectin–ligand interaction

The crystal structure of the complex of meso-tetrasulfonatophenylporphyrin (H(2)TPPS) with jack fruit (Artocarpus integriflora) agglutinin (jacalin) has been determined at 1.8 A resolution. A porphyrin pair is sandwiched between two symmetry-related jacalin monomers in the crystal, leading to a cross-linking network of protein molecules. Apart from the stacking interactions, H(2)TPPS also forms hydrogen bonds, some involving water bridges, with jacalin at the carbohydrate-binding site. The residues that are involved in rendering galactopyranoside specificity to jacalin undergo conformational adjustments in order to accommodate the H(2)TPPS molecule. The water molecules at the carbohydrate-binding site of jacalin cement the jacalin-porphyrin interactions, optimizing their complementarity. Interactions of porphyrin with jacalin are relatively weak compared with those observed between galactopyranoside and jacalin, perhaps because the former largely involves water-mediated hydrogen bonds. While H(2)TPPS binds to jacalin at the carbohydrate-binding site as in the case of ConA, its mode of interaction with jacalin is very different. H(2)TPPS does not enter the carbohydrate-binding cavity of jacalin. Instead, it sits over the binding site. While the porphyrin binding is mediated by replicating the hydrogen-bonding network of mannopyranoside through the sulfonate atoms in the case of ConA, the plasticity associated with the carbohydrate-binding site accommodates the pluripotent porphyrin molecule in the case of jacalin through an entirely different set of interactions.

Individual and combined effect of (+/-)-alpha-hydrastine and (+/-)-beta-hydrastine on spore germination of some fungi

(+/-)-alpha-Hydrastine and (+/-)-beta-hydrastine were isolated from Corydalis longipes; both exhibited considerable efficacy against spore germination of some saprophytic and phytopathogenic fungi. While (+/-)-alpha-hydrastine was effective against most of the fungi, Helminthosporium echinoclova was least affected even at the highest dose (150 ppm). (+/-)-beta-Hydrastine was equally effective against several fungi. Mixture of both compounds was more effective than each one individually. Helminthosporium species were again the most resistant toward the mixture. The effect of both alkaloids independently on germination and development of E. pisi conidia on excised pea leaves was also shown. After pre-inoculation with (+/-)-alpha-hydrastine, the effect was more pronounced than the addition post-inoculation; maximum inhibition occurred at 200 ppm. (+/-)-beta-Hydrastine also reduced germination of conidia but was less effective than (+/-)-alpha-hydrastine. The number of primary and secondary branches of conidia and number of appressoria were not affected significantly by either compound.

Regulation of Drosophila TRPL channels by immunophilin FKBP59

Transient receptor potential and transient receptor potential-like (TRPL) are Ca(2+)-permeable cation channels found in Drosophila photoreceptor cells associated with large multimeric signaling complexes held together by the scaffolding protein, INAD. To identify novel proteins involved in channel regulation, Drosophila INAD was used as bait in a yeast two-hybrid screen of a Drosophila head cDNA library. Sequence analysis of one identified clone showed it to be identical to the Drosophila homolog of human FK506-binding protein, FKBP52 (previously known as FKBP59). To determine the function of dFKBP59, TRPL channels and dFKBP59 were co-expressed in Sf9 cells. Expression of dFKBP59 produced an inhibition of Ca(2+) influx via TRPL in fura-2 assays. Likewise, purified recombinant dFKBP59 produced a graded inhibition of TRPL single channel activity in excised inside-out patches when added to the cytoplasmic membrane surface. Immunoprecipitations from Sf9 cell lysates using recombinant tagged dFKBP59 and TRPL showed that these proteins directly interact with each other and with INAD. Addition of FK506 prior to immunoprecipitation resulted in a temperature-dependent dissociation of dFKBP59 and TRPL. Immunoprecipitations from Drosophila S2 cells and from fly head lysates demonstrated that dFKBP59, but not dFKBP12, interacts with TRPL in vivo. Likewise, INAD immunoprecipitates with dFKBP59 from S2 cell and head lysates. Immunocytochemical evaluation of thin sections of fly heads revealed specific FKBP immunoreactivity associated with the eye. Site-directed mutagenesis showed that mutations of P702Q or P709Q in the highly conserved TRPL sequence (701)LPPPFNVLP(709) eliminated interaction of the TRPL with dFKBP59. These results provide strong support for the hypothesis that immunophilin dFKBP59 is part of the TRPL-INAD signaling complex and plays an important role in modulation of channel activity via interaction with conserved leucyl-prolyl dipeptides located near the cytoplasmic mouth of the channel.

Functional equality in the absence of structural similarity: an added dimension to molecular mimicry

The crystal structure of meso-tetrasulfonatophenylporphyrin complexed with concanavalin A (ConA) was determined at 1.9 A resolution. Comparison of this structure with that of ConA bound to methyl alpha-d-mannopyranoside provided direct structural evidence of molecular mimicry in the context of ligand receptor binding. The sulfonatophenyl group of meso-tetrasulfonatophenylporphyrin occupies the same binding site on ConA as that of methyl alpha-d-mannopyranoside, a natural ligand. A pair of stacked porphyrin molecules stabilizes the crystal structure by end-to-end cross-linking with ConA resulting in a network similar to that observed upon agglutination of cells by lectins. The porphyrin binds to ConA predominantly through hydrogen bonds and water-mediated interactions. The sandwiched water molecules in the complex play a cementing role, facilitating favorable binding of porphyrin. Seven of the eight hydrogen bonds observed between methyl alpha-d-mannopyranoside and ConA are mimicked by the sulfonatophenyl group of porphyrin after incorporating two water molecules. Thus, the similarity in chemical interactions was manifested in terms of functional mimicry despite the obvious structural dissimilarity between the sugar and the porphyrin.

Immunological implications of structural mimicry between a dodecapeptide and a carbohydrate moiety

The immunogenicity and antibody cross-reactivity of two chemically different but structurally equivalent molecular mimics were analyzed by presenting them to the immune system in different modes. The observed differences in IgM and IgG responses in terms of cross-reactivity with the mimicking antigen could reflect the differential proliferative abilities of the corresponding B-cells. Modification of the T-cell help, either by using a promiscuous T-cell epitope or by prepriming, led to the shift in the antibody response towards the mimicking epitope. Also, the anti-sugar antibodies could be boosted using a carbohydrate mimicking peptide on cross-immunization. Thus, the carbohydrate-peptide mimicry appears to be a topological quasi-equivalence reflected differently in terms of antibody response during maturation.

Implantation malignancy after laparoscopic cholecystectomy

Laparoscopic cholecystectomy may result in spillage of gall bladder contents during dissection or delivery of gall bladder through the umbilical port. We report a 50-year-old man who underwent laparoscopic cholecystectomy for suspected calculous cholecystitis. Histology showed a single focus of adenocarcinoma in the gall bladder. There was spillage of gall bladder contents at the umbilical port during delivery. Six months later, he developed adenocarcinoma at the port site. This was treated by wide excision.

Global impairment of coronary blood flow in the setting of acute coronary syndromes (a RESTORE substudy). Randomized Efficacy Study of Tirofiban for Outcomes and Restenosis

Acute coronary syndromes result in a global impairment of coronary blood flow with nonculprit artery blood flow being associated with culprit artery flow and vice versa. Improvements in nonculprit artery flow are related to improvements in culprit artery flow after percutaneous intervention; nonculprit arteries with abnormal flow sustain greater improvements in their flow after culprit artery intervention.

Hysteroscopic management of intra-uterine devices with lost strings

We report a series of 38 patients with intra-uterine devices with lost strings where hysteroscopic aid was required after routine retrieval procedures failed. Thirty-five intra-uterine devices could be removed easily with hysteroscope. In one patient a fragmented Lippes Loop was removed piecemeal hysteroscopically. Laparotomy was required in only one patient, for an extra-uterine Copper T. Hysteroscopy is thus a simple, safe and effective method for removing misplaced intra-uterine devices.

Haemostatic changes in children with cyanotic and acyanotic congenital heart disease

This study was undertaken to screen children with congenital heart disease for coagulation abnormalities and to compare the groups of cyanotic and acyanotic children with congenital heart disease with respect to abnormalities of the coagulation system. Following investigations were done in all the patients: complete blood count, erythrocyte sedimentation rate, peripheral smear examination, bleeding time, prothrombin time, activated partial thromboplastin time, assay of fibrinogen, D-dimer, factors VII and VIII and antithrombin III. Red cell indices were determined in 12 control, 12 acyanotic and 20 cyanotic children. Twenty-five patients each, with echocardiographically proven cyanotic and acyanotic congenital heart disease under 12 years of age constituted the study group; as many children of the same age group were included as the control group. The results showed isolated abnormalities of laboratory tests with equal frequency (28%) in acyanotic and cyanotic groups but coexisting abnormalities of more than one test were seen in significantly larger number of cyanotic children (5/25 and 16/25, respectively). A significant association was noted between thrombocytopenia and a high haematocrit in cyanotic patients. It is concluded that laboratory abnormalities of tests of haemostasis are more common in cyanotic congenital heart disease patients. The patterns of laboratory abnormalities suggest a chronic compensated disseminated intravascular coagulation at a subclinical level, reduced synthesis of clotting factors and/or deranged platelet aggregation in different subgroups of patients.

Structural basis of functional mimicry between carbohydrate and peptide ligands of con A

Crystallographic studies have shown independent binding sites for sugar and peptide ligands of concanavalin A, although they were considered functional mimics based on biochemical experiments. The topological correlation of 12-residue peptide with different carbohydrate ligands of concanavalin A showed similarity between trimannose and the YPY region of the peptide establishing structural mimicry. Molecular docking of trimannose and the YPY motif on the reciprocal binding sites revealed equivalent interactions and energetics implying that the peptide-binding sites may constitute additional sugar-binding subsites of concanavalin A. The binding of a mannose-rich neoglycoprotein with significantly higher affinity compared with that of the methyl alpha-d-mannopyranoside is consistent with this interpretation.