Evaluation of ADRB2 and OATP2A1 genetic polymorphisms in Indian patients with primary open-angle glaucoma

The emergence of adrenergic β2-receptor (ADRB2) blockers has revolutionized glaucoma treatment, while the discovery of prostaglandin analogs has further expanded therapeutic options. Organic anion transporting polypeptide 2A1 (OATP2A1/SLCO2A1) facilitates the corneal transport of topical prostaglandins into anterior segment of eye. Our study aims to elucidate the prevalence of genetic polymorphisms in the ADRB2 and OATP2A1 to address variations in therapeutic responses among glaucoma patients. The study cohort comprised primary open-angle glaucoma patients (POAG, n = 77), compared to non-glaucomatous controls (n = 60) to identify polymorphisms rs1042713 (Arg16Gly, A > G) and rs1042714 (Gln27Glu, C > G) in the ADRB2 gene and rs34550074 (Ala396Thr, A > G) in OATP2A1 gene, using Sanger sequencing. Among the enrolled subjects (n = 137), the POAG group exhibited significantly elevated intraocular pressure ( P  < 0.001) and cup-to-disc ratio ( P  < 0.0001). The GA genotype of rs1042713 ( P  < 0.01) and the GG genotype of rs1042714 ( P  < 0.05) were positively associated with POAG, while rs34550074 ( P  > 0.05) showed no significant correlation with the disease. This study reveals the association of the ADRB2 gene polymorphisms with POAG, whereas OATP2A1 polymorphism did not show significant correlation.

Untargeted metabolomics in the aqueous humor reveals the involvement of TAAR pathway in glaucoma

Understanding the metabolic dysfunctions and underlying complex pathological mechanisms of neurodegeneration in glaucoma could help discover disease pathways, identify novel biomarkers, and rationalize newer therapeutics. Therefore, we aimed to investigate the local metabolomic alterations in the aqueous humor and plasma of primary glaucomatous patients. This study cohort comprised primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG), and cataract control groups. Aqueous humor and plasma samples were collected from patients undergoing trabeculectomy or cataract surgery and subjected to high-resolution mass spectrometry (HRMS) analysis. Spectral information was processed, and the acquired data were subjected to uni-variate as well as multi-variate statistical analyses using MetaboAnalyst ver5.0. To further understand the localized metabolic abnormalities in glaucoma, metabolites affected in aqueous humor were distinguished from metabolites altered in plasma in this study. Nine and twelve metabolites were found to be significantly altered (p < 0.05, variable importance of projection >1 and log2 fold change ≥0.58/≤ -0.58) in the aqueous humor of PACG and POAG patients, respectively. The galactose and amino acid metabolic pathways were locally affected in the PACG and POAG groups, respectively. Based on the observation of the previous findings, gene expression profiles of trace amine-associated receptor-1 (TAAR-1) were studied in rat ocular tissues. The pharmacodynamics of TAAR-1 were explored in rabbits using topical administration of its agonist, β-phenyl-ethylamine (β-PEA). TAAR-1 was expressed in the rat's iris-ciliary body, optic nerve, lens, and cornea. β-PEA elicited a mydriatic response in rabbit eyes, without altering intraocular pressure. Targeted analysis of β-PEA levels in the aqueous humor of POAG patients showed an insignificant elevation. This study provides new insights regarding alterations in both localized and systemic metabolites in primary glaucomatous patients. This study also demonstrated the propensity of β-PEA to cause an adrenergic response through the TAAR-1 pathway.

Undiagnosed and Uncontrolled Hypertension and Access to Health Care among Residents of an Urban Area of Eastern Nepal: a Cross-sectional Study

Background The burden and complication of hypertension is increasing as most of the people living with hypertension are unaware of their condition and those who are already diagnosed with it do not have their blood pressure under control. Objective To assess the prevalence of undiagnosed and uncontrolled hypertension among residents of Itahari sub metropolitan city of eastern Nepal, along with its associated socio demographic and behavioral risk factors and access to health care services. Method Cross sectional study was conducted in five wards of Itahari, among 1161 participants, using population proportionate to sample size sampling technique. Face to face interview was conducted with participants for data collection applying semi- structured questionnaire and physical measurement like blood pressure, weight and height. Result Prevalence of hypertension was 26.5% includingundiagnosed 11.0% and previously diagnosed 15.5%. Among diagnosed, 76.6% had uncontrolled blood pressure and 56.70% were taking anti-hypertensive medicine, and 7.8% were under Ayurvedic medicine. More than 70% participants preferred private health facility for treatment and 22.7% had faced financial barrier to seek healthcare. About 64% of participants did not visit health services or had visited only once in past six months. Increasing age, Body Mass Index (BMI), smoking status and positive family history were found to be significantly associated with hypertension at < 0.05 level. Conclusion Prevalence of hypertension is high and awareness regarding available health services in local primary health center and its utilization is lacking among participants. Regular screening program for hypertension and awareness program to disseminate the knowledge of availability of primary health center should be conducted.

Retinal Pigment Epithelium in Human Donor Eyes Contains Higher Levels of Bisretinoids Including A2E in Periphery than Macula

Purpose

With age, human retinal pigment epithelium (RPE) accumulates bisretinoid fluorophores that may impact cellular function and contribute to age-related macular degeneration (AMD). Bisretinoids are comprised of a central pyridinium, dihydropyridinium, or cyclohexadiene ring. The pyridinium bisretinoid A2E has been extensively studied, and its quantity in the macula has been questioned. Age-changes and distributions of other bisretinoids are not well characterized. We measured levels of three bisretinoids and oxidized A2E in macula and periphery in human donor eyes of different ages.

Methods

Eyes (N = 139 donors, 61 women and 78 men, aged 40–80 years) were dissected into 8 mm diameter macular and temporal periphery punches. Using liquid chromatography – electrospray ionization – mass spectrometry (LC-ESI-MS) and an authentic synthesized standard, we quantified A2E (ng). Using LC-ESI-MS and a 50-eye-extract of A2E, we semiquantified A2E and 3 other compounds (eye extract equivalent units [EEEUs): A2-glycerophosphoethanolamine (A2GPE), dihydropyridine phosphatidyl ethanolamine (A2DHPE), and monofuranA2E (MFA2E).

Results

A2E quantities in ng and EEEUs were highly correlated (r = 0.97, P < 0.001). From 262 eyes, 5 to 9-fold higher levels were observed in the peripheral retina than in the macula for all assayed compounds. A2E, A2DHPE, and MFA2E increased with age, whereas A2GPE remained unaffected. No significant right-left or male-female differences were detected.

Conclusions

Significantly higher levels were observed in the periphery than in the macula for all assayed compounds signifying biologic differences between these regions. Levels of oxidized A2E parallel native A2E and not the distribution of retinal illuminance. Data will assist with the interpretion of clinical trial outcomes of agents targeting bisretinoid-related pathways.

Elevated histamine levels in aqueous humor of patients with glaucoma

PURPOSE

Neurotransmitters (NTs) are the key mediators of essential ocular functions, such as processing the visual functions of the retina, maintaining homeostasis of aqueous humor, and regulating ocular blood flow. This study aims to determine variations in the levels of L-glutamate and γ-aminobutyric acid (GABA), histaminergic, adrenergic, cholinergic, and serotonergic NTs in patients with primary glaucoma versus patients with cataract.

METHODS

This case-control study involved three age-matched groups of patients with primary open angle glaucoma (POAG, n = 14), primary angle closure glaucoma (PACG, n = 21), and cataract (control, n = 19). Patients' aqueous humor and plasma were collected, snap frozen at -80 °C, and subjected to ultrasensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis for quantification of NTs.

RESULTS

Baseline intraocular pressure and the cup-to-disc ratio were found to be statistically significantly elevated in the POAG and PACG groups compared to the cataract control group. In aqueous humor, histamine was found to be statistically significantly elevated (5-fold, p<0.0001), whereas 1-methyl histamine was statistically significantly decreased (p<0.05) in POAG compared to the control group. A statistically significant increase in L-glutamate and GABA was observed among both patient groups with glaucoma compared to the cataract control group. Adrenaline was found to be elevated only in the PACG group (2.7-fold, p<0.05). No statistically significant difference was observed among the plasma NT levels between the groups.

CONCLUSIONS

This study demonstrated the prominent role of the histaminergic system apart from autonomic mechanisms in the progression of glaucoma. Elevated L-glutamate and GABA could be due to retinal ganglionic cell death. Further studies are required to evaluate the effects of histamine on Müller cell dysfunction.

Andrographolide - A prospective remedy for chikungunya fever and viral arthritis

AIM

Andrographolide, the major bioactive compound of the plant Andrographis paniculata, exerts anti-inflammatory, cyto-, neuro- and hepato-protective effects. Traditional remedies for infectious diseases include A. paniculata for maladies like fever, pain, rashes which are associated with chikungunya and other arboviral diseases. Since andrographolide and A. paniculata have potent antiviral properties, the present review aims to provide a comprehensive report of symptoms and immunological molecules involved in chikungunya virus (CHIKV) infection and the therapeutic role of andrographolide in the mitigation of chikungunya and associated symptoms.

MATERIALS AND METHODS

Studies on the therapeutic role of A. paniculata and andrographolide in chikungunya and other viral infections published between 1991 and 2021 were searched on various databases.

RESULTS AND DISCUSSION

The havoc created by chikungunya is due to the associated debilitating symptoms including arthralgia and myalgia which sometimes remains for years. The authors reviewed and summarized the various symptoms and immunological molecules related to CHIKV replication and associated inflammation, oxidative and unfolded protein stress, apoptosis and arthritis. Additionally, the authors suggested andrographolide as a remedy for chikungunya and other arboviral infections by highlighting its role in the regulation of molecules involved in unfolded protein response pathway, immunomodulation, inflammation, virus multiplication, oxidative stress, apoptosis and arthritis.

CONCLUSION

The present review demonstrated the major complications associated with chikungunya and the role of andrographolide in alleviating the chikungunya associated symptoms to encourage further investigations using this promising compound towards early development of an anti-CHIKV drug. Chemical Compound studied: andrographolide (PubChem CID: 5318517).

Re-exposure to alarmin HMGB1 and cytokine IL-1 beta induces differential innate immune response generation in mouse brain

Innate immune memory, a crucial mechanism of epigenetically mediated myeloid cell plasticity, alters subsequent immune responses majorly by two types of immunological imprinting, training, and tolerance. Recent pioneer studies provided proof-of-principle for generation of both types of innate immune memory in brain macrophage, microglial cells. This novel study was designed to investigate whether the pattern of immune response generation, induced by peripheral administration of recombinant alarmin HMGB1, alone and in combination with other recombinant cytokines, is affected by prior exposure. The experimental outcomes revealed that full length recombinant HMGB1 exposure for seven consecutive days exhibit inflammatory response as evidenced by enhanced expression of inflammatory biomarkers and neurodegeneration. In contrary, combined doses of HMGB1 and IL-1β, for three and seven consecutive days, exhibited lower inflammatory state compared to its alone HMGB1 counterpart. The immune tolerance state was evident by microglial polarization towards non-reactive M2 state, lower astrocyte activation, epigenetic reprogramming, and decreased neurodegeneration. This is the first demonstration that HMGB1 and IL-1β priming can differentially affect inflammation in the brain when a host is confronted with a second, third stimulus or so on. The findings were further validated by suppressing major regulators of epigenetic reprogramming, by intranasal delivery of specific siRNAs targeting those regulators. These results may provide new evidence for the involvement of recombinant endogenous cytokine induced generation of innate immune tolerance within microglial cells and indicated the possible potential role in mediating cognitive and behavioural alterations during inflammatory diseases.

Evaluation of the Presence and Functional Importance of Nucleoside Transporters in Lacrimal Gland for Tear Disposition of Intravenously Injected Substrate in Rabbits

Purpose: Purpose of the current study was to assess the presence and functionality of the nucleoside transporters in the lacrimal gland for the tear disposition of its substrate given intravenously in rabbits.Materials and Methods: Rabbits were divided into two groups - control and blocker pretreated. The blocker pretreated group received 5 mg/kg of dipyridamole 30 min before ribavirin (substrate), which was given at a dose of 2.5 mg/kg. All the treatments were given intravenously. Blood and tear samples were collected at 5, 15, 30, 60, 90, 120, 180, 240, 300 and 360 min (n = 4; each time point) after substrate administration. Tear samples were collected on Schirmer's strips, and plasma was separated immediately after blood collection. All the samples were stored at -80°C until analysis by LC-MS/MS.Results: Plasma ribavirin concentration for blocker pretreated group showed significantly (p < .05) higher levels at 5, 15, 30, 60, 120, 180 and 300 min as compared to the control group. Similarly, tear ribavirin concentration for blocker pretreated group also showed a significant (p < .05) increase at 5, 15, 60, 90, 180, 240 and 300 min compared to the control group. Plasma and tear AUC_(0-6) for blocker pretreated group was 1.7 (p < .001) and 2.42 (p < .001) folds higher in a significant manner as compared to the control group, respectively. Percentage penetration of ribavirin from plasma to tears was also different between control and blocker pretreated group. Permeation ratio of ribavirin from plasma to tear for blocker pretreated group was found to be 1.4-folds higher in a significant (p < .05) manner.Conclusion: It is evident from the results that nucleoside transporters are present in lacrimal gland. The blocker treatment induced increase in tear transport of ribavirin indicates the possibility of the presence of nucleoside transporters on the apical side of lacrimal acinar cells in the uptake position.

Genetic gains with rapid-cycle genomic selection for combined drought and waterlogging tolerance in tropical maize (Zea mays L.)

Rapid cycle genomic selection (RC-GS) helps to shorten the breeding cycle and reduce the costs of phenotyping, thereby increasing genetic gains in terms of both cost and time. We implemented RC-GS on two multi-parent yellow synthetic (MYS) populations constituted by intermating ten elite lines involved in each population, including four each of drought and waterlogging tolerant donors and two commercial lines, with proven commercial value. Cycle 1 (C₁ ) was constituted based on phenotypic selection and intermating of the top 5% of 500 S₂ families derived from each MYS population, test-crossed and evaluated across moisture regimes. C₁ was advanced to the next two cycles (C₂ and C₃ ) by intermating the top 5% selected individuals with high genomic estimated breeding values (GEBVs) for grain yield under drought and waterlogging stress. To estimate genetic gains, population bulks from each cycle were test-crossed and evaluated across locations under different moisture regimes. Results indicated that the realised genetic gain under drought stress was 0.110 t ha^-1 yr^-1 and 0.135 t ha^-1 yr^-1 , respectively, for MYS-1 and MYS-2. The gain was less under waterlogging stress, where MYS-1 showed 0.038 t ha^-1 yr^-1 and MYS-2 reached 0.113 t ha^-1 yr^-1 . Genomic selection for drought and waterlogging tolerance resulted in no yield penalty under optimal moisture conditions. The genetic diversity of the two populations did not change significantly after two cycles of GS, suggesting that RC-GS can be an effective breeding strategy to achieve high genetic gains without losing genetic diversity.

Andrographolide attenuates complete freund's adjuvant induced arthritis via suppression of inflammatory mediators and pro-inflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional plant-derived medicines have enabled the mankind in curing the wide spectrum of diseases throughout the ages. Andrographis paniculata (Burm.f.) Nees, is one of the traditional plant used as a folk medicine for the management of inflammation, arthritis, viral-bacterial infections and other ailments in India, China, Malaysia and other South-East Asian countries. Its major bioactive compound; andrographolide, a diterpenoid, also exerts cytoprotective properties and is reported to be effective in neuroprotection, hepatoprotection, etc. AIM: The study is aimed to explore the role of andrographolide in treatment of complete freund's adjuvant (CFA) induced arthritis.

MATERIALS AND METHODS

The influx of immune cells, release of pro-inflammatory cytokines and subsequent accumulation of synovial fluid (swelling) and pain manifest into the disease. The present study used CFA induced Balb/c mice model and treated them intraperitoneally with andrographolide and dexamethasone (used as a positive control) on alternate days for six days. After 6 days, blood and peritoneal macrophages were collected to evaluate the expression of various arthritic markers and paw edema was measured on all days.

RESULTS

The in vitro and ex vivo experiments showed that andrographolide treated animal group had reduced paw edema, cell cytotoxicity and nitric oxide production than dexamethasone treated animal group. Further, the study revealed the mechanistic role of andrographolide in treatment of arthritis by suppressing battery of molecules like COX-2, NF-κB, p-p38, CD40, TNF-α, IL-1β and IL-6 involved in arthritis.

CONCLUSION

The study showed the potent anti-arthritic effects of andrographolide and warrants further investigations on andrographolide for the development of safe and effective anti-arthritic drug.

CXCR7: A key neuroprotective molecule against alarmin HMGB1 mediated CNS pathophysiology and subsequent memory impairment

High mobility group box 1 (HMGB1) is an endogenous alarmin that drives the pathogenesis of neurodegenerative disorders including cognitive decline. Therefore, HMGB1 is thought to be a common biomarker as well as promising therapeutic target for neuroinflammation associated with neurocognitive disorders. Here, for the first time, we have unmasked the potential inhibitory effect of a novel receptor of HMGB1-CXCL12 complex; atypical chemokine receptor 3 (ACKR3/CXCR7) on HMGB1 induced glial phenotype switching, neuroinflammation, and subsequent memory loss. Upregulation of CXCR7 inhibits HMGB1-CXCL12 complex induced peripheral immune cells infiltration to CNS by regulating blood-brain barrier (BBB) integrity in HMGB1 induced dementia model of mice. Whereas, gene knockdown study by RNA interference (non-invasive intranasal delivery to animal model) shows CXCR7 ablation aggravates inflammatory responses in hippocampus region and immune cell infiltration to CNS tissue by breached BBB. This study also indicates the important role of CXCR7 molecule in maintaining CNS homeostasis by balancing M1/M2 microglia, A1/A2 astrocytes, long term potentiation/long term depression markers which ultimately ameliorates HMGB1 induced neurodegeneration, synaptic depression and memory loss (assessed by both radial arm maze and Morris water maze) in male mice model of dementia. Overall, the study summarizes several significant protective functions afforded by CXCR7 against HMGB1 induced disbalance in neuroimmunological axis, neurodegeneration and memory loss and thereby provides a new paradigm for strategic development of novel therapeutics against neurodegenerative diseases with dementia as a common symptom.

Ocular kinetics and safety of intravitreally injected angiotensin converting enzyme inhibitor lisinopril

Background and objectives

The study investigated the intravitreal safety and vitreous disposition of lisinopril, an angiotensin converting enzyme inhibitor in rabbits for its projected use in retinopathy.

Methods

For the safety study, following the baseline ERG recording and fundus photography, 40 µg/50 µl of lisinopril sterile injection was injected unilaterally in the rabbit eyes (n = 4), where other eye served as a control. The electroretinogram and fundus images were obtained at 24, 48, 72 and 168 h following the intravitreal injection. For pharmacokinetics evaluation of the lisinopril, one eye of each rabbit (n = 4) received an intravitreal injection of lisinopril (40 µg/50 µl). The concentration of lisinopril in the ocular tissues, humours, plasma, lung, kidney and liver were measured through ESI-LC-MS/MS.

Results

Upon the electroretinography studies, no significant difference was observed in the ERG pattern in the lisinopril injected eye when compared to the baseline of the respective animals till the 7th day of the study. In the fundus imaging, no morphological changes were observed in the retina of the animal. The concentration of the lisinopril was found to be above to the IC50 in the retina-choroid till 36 h. The concentration found in the plasma and body tissues were many folds less than the IC50 of the lisinopril.

Conclusions

Intravitreal injection of 40 µg/50 µl of lisinopril found to be safe in the rabbit eye as evidenced by the electroretinography and fundus imaging studies. The average half-life of lisinopril is 12.6 h and the above-mentioned dose able to sustain its IC50 value till the 36 h.

2D Effective Electron Mass at the Fermi Level in Accumulation and Inversion Layers of MOSFET Nano Devices

In this paper an attempt is made to study the 2D Fermi Level Mass (FLM) in accumulation and inversion layers of nano MOSFET devices made of nonlinear optical, III-V, ternary, Quaternary, II-VI, IV-VI, Ge and stressed materials by formulating 2D carrier dispersion laws on the basis of k → ⋅ p → ⋅ formalism and considering the energy band constants of a particular material. It is observed taking accumulation and inversion layers of Cd3As2, CdGeAs2, InSb, Hg1-xCdxTe and In1-xGaxAsyP1-y lattice matched to InP, CdS, GaSb and Ge as examples that the FLM depends on sub band index for nano MOSFET devices made of Cd3As2 and CdGeAs2 materials which is the characteristic features such 2D systems. Besides, the FLM depends on the scattering potential in all the cases and the same mass changes with increasing surface electric field. The FLM exists in the band gap which is impossible without heavy doping.

A Modified Mean Gray Wolf Optimization Approach for Benchmark and Biomedical Problems

A modified variant of gray wolf optimization algorithm, namely, mean gray wolf optimization algorithm has been developed by modifying the position update (encircling behavior) equations of gray wolf optimization algorithm. The proposed variant has been tested on 23 standard benchmark well-known test functions (unimodal, multimodal, and fixed-dimension multimodal), and the performance of modified variant has been compared with particle swarm optimization and gray wolf optimization. Proposed algorithm has also been applied to the classification of 5 data sets to check feasibility of the modified variant. The results obtained are compared with many other meta-heuristic approaches, ie, gray wolf optimization, particle swarm optimization, population-based incremental learning, ant colony optimization, etc. The results show that the performance of modified variant is able to find best solutions in terms of high level of accuracy in classification and improved local optima avoidance.

A New Hybrid MGBPSO-GSA Variant for Improving Function Optimization Solution in Search Space

In this article, a newly hybrid nature-inspired approach (MGBPSO-GSA) is developed with a combination of Mean Gbest Particle Swarm Optimization (MGBPSO) and Gravitational Search Algorithm (GSA). The basic inspiration is to integrate the ability of exploitation in MGBPSO with the ability of exploration in GSA to synthesize the strength of both approaches. As a result, the presented approach has the automatic balance capability between local and global searching abilities. The performance of the hybrid approach is tested on a variety of classical functions, ie, unimodal, multimodal, and fixed-dimension multimodal functions. Furthermore, Iris data set, Heart data set, and economic dispatch problems are used to compare the hybrid approach with several metaheuristics. Experimental statistical solutions prove empirically that the new hybrid approach outperforms significantly a number of metaheuristics in terms of solution stability, solution quality, capability of local and global optimum, and convergence speed.

Vitreous Amyloidosis: Ocular, Systemic, and Genetic Insights

PURPOSE

To report the unique clinical and surgical characteristics encountered in eyes with vitreous amyloidosis. Systemic evaluation and visual outcome after vitrectomy are discussed. A novel mutation in the transthyretin gene (TTR) in Indian patients with familial amyloid polyneuropathy (FAP) is described.

DESIGN

Retrospective, observational study.

PARTICIPANTS

Ten eyes of 5 patients from 2 pedigrees with a diagnosis of vitreous amyloidosis.

METHODS

Detailed history, pedigree charting, systemic and ocular examination of 10 eyes (5 patients from 2 pedigrees) were carried out. Tests were performed to rule out vitreitis, retinal vasculitis, vitreous hemorrhage, and systemic amyloidosis. Genetic analysis to identify the mutation was performed in 1 patient. Vitreous biopsy, followed by 25-gauge pars plana vitrectomy, was performed in the same sitting in all cases. Samples were sent for Congo red staining and polarized microscopy. Patients were followed up on days 1, 7, and 28 and then every 2 months. Visual acuity assessment, intraocular pressure measurement, and fundus examination were performed each time.

MAIN OUTCOME MEASURES

Mutations in TTR and postoperative visual acuity.

RESULTS

Mean age at presentation was 32 years, with a 3:2 male-to-female distribution. Family history was positive in all patients. Nine eyes had pseudopodia lentis, whereas all 10 had glass wool-like vitreous. Glaucoma developed in 1 patient (2 eyes). Waxy paper-like vitreous with firm vitreous adhesions beyond major arcades and along retinal vessels was noted during surgery in all eyes. Congo red staining and apple green birefringence demonstrated vitreous amyloidosis. The mean preoperative best-corrected visual acuity (BCVA) was 1.39±0.64 logarithm of the minimum angle of resolution (logMAR), whereas the postoperative BCVA improved to 0.17±0.07 logMAR (P = 0.004). Gene sequencing revealed a phenylalanine→isoleucine mutation in the 33rd position of exon 2 of TTR in 1 patient of 1 pedigree, confirming the diagnosis of FAP. Two patients subsequently were found to have sensorimotor autonomic neuropathy, whereas 2 others had subclinical autonomic dysfunction.

CONCLUSIONS

The clinical clues, management strategy, surgical characteristics, vitrectomy outcomes, and significance of systemic evaluation in vitreous amyloidosis are highlighted. A novel single mutation (Phe33Ile) in a case of FAP with vitreous amyloidosis from India is reported.

Cardiovascular involvement in severe malaria: A prospective study in Ranchi, Jharkhand

BACKGROUND & OBJECTIVES

Malaria is considered as the most important parasitic disease of humans, causing seri- ous illness that can be fatal, if not diagnosed and treated immediately. It is a multisystem disorder affecting nearly every system of the body. The aim of the present study was to evaluate the involvement of cardiovascular system in severe malaria using non-invasive methods.

METHODS

This prospective study was conducted on patients of severe malaria who were admitted between June and November 2015 in the Department of Medicine, Rajendra Institute of Medical Sciences and Hospital, Ranchi, Jharkhand, India. A total of 27 cases (18 males and 9 females; age ranging between 15 and 70 yr) of severe malaria (P. falciparum 24; P. vivax 1; mixed 2) were diagnosed by microscopic examination of peripheral blood smear and bivalent rapid diagnostic test (RDT) kit. The assessment of cardiovascular system was done by clinical examination, chest X-ray, ECG and transthoracic echocardiography.

RESULTS

In all, 7 (26%) patients were found to be suffering from circulatory failure, out of which one was P. vivax case and rest were cases of P. falciparum infection with high parasite density. One patient died due to cardiovascular collapse. ECG revealed sinus bradycardia [Heart rate (HR): 40-60] in 7% of the cases, extreme tachycardia (HR: 120-150) in 3.7% of cases and premature arterial ectopic with tachycardia in 3.7% of patients (p <0.05). The echo- cardiographic findings were global hypokinesia with decreased left ventricular ejection fraction (<55%) in 11.1%, grade 1 left ventricular diastolic dysfunction in 3.7%, mild tricuspid regurgitation (TR) with mild pulmonary artery hypertension (PAH) in 3.7% and mild pericardial effusion in 3.7% of the cases. The ECG and echocardiography changes indicated myocardial involvement in severe malaria.

INTERPRETATION & CONCLUSION

The present study indicated involvement of cardiovascular system in severe malaria as evidenced from ECG and echocardiography. The study also revealed that cardiovascular instabilities are common in falciparum malaria, but can also be observed in vivax malaria.

Augmentation of humoral and cellular immunity in response to Tetanus and Diphtheria toxoids by supercritical carbon dioxide extracts of Hippophae rhamnoides L. leaves

Hippophae rhamnoides L. commonly known as Seabuckthorn (SBT), a wild shrub of family Elaegnacea, has extensively used for treating various ailments like skin diseases, jaundice, asthma, lung troubles. SBT leaves have been reported to possess several pharmacological properties including immunomodulatory, antioxidant, anti-inflammatory, antimicrobial and tissue regeneration etc. The present study was undertaken to evaluate the adjuvant property of supercritical carbon dioxide extracts (SCEs 300ET and 350ET) of SBT leaves in balb/c mice immunized with Tetanus and Diphtheria toxoids. The dynamic changes in the immune response were measured in terms of humoral and cell-mediated immune responses. We have seen the effect of SCEs on immunoglobulin subtypes and secondary immune response generation. In addition, the effect of SCEs on antigen specific cellular immunity was evaluated. Our results show that SCEs 300ET and 350ET significantly enhanced antibody titers in response to both TT and DT antigens. The secondary immune response generated was significantly increased in case of TT immunized animals. SCEs also enhanced cytokine levels (IFN-γ, IL-4, TNF-α and IL-1β) and increased lymphoproliferation. Besides, both SCEs did not show any toxic effects. Therefore, the study suggests that SCEs are safe and have potent immunostimulatory activity and hence, seems to be a promising balanced Th1 and Th2 directing immunological adjuvant for various veterinary as well as human vaccines.

Distribution and Biology of Mallada desjardinsi (Neuroptera: Chrysopidae) in India and Its Predatory Potential Against Aleurodicus dispersus (Hemiptera: Aleyrodidae)

In this study, we report the prevalence of Mallada desjardinsi (Navas) in seven geographical regions of India and provide the first report of its kind outlining the preying of all stages of the spiraling whitefly, Aleurodicus dispersus Russell, by M. desjardinsi Sampling was conducted in seven regions of two provinces in India, Bengaluru (Karnataka) and Tiruppur (Tamil Nadu), which demonstrated that M. desjardinsi populations were most dense at the former and least at the later. To the best of our knowledge, this is the first report of its kind outlining observations regarding the biology and feeding potential of M. desjardinsi on A. dispersus under laboratory conditions. It was observed that the second nymphal stadium of A. dispersus was most preferred prey for M. desjardinsi and the least preferred was the A. dispersus adult. It was also seen that the third stadium of M. desjardinsi consumed more A. dispersus individuals than any other life stages. The longevity of female and the total developmental period of M. desjardinsi were computed as 27.6 ± 1.69 and 24.1 ± 0.99 d, respectively. The average total number of eggs laid by the M. desjardinsi female was 211.1 ± 6.35 eggs. M. desjardinsi was observed to be extremely efficient in terms of prey searching and predatory potential with respect to A. dispersus The results of this study indicate strongly that M. desjardinsi has the potential to be used for the control of A. dispersus.

Comparative Proteomic Analysis of Advanced Ovarian Cancer Tissue to Identify Potential Biomarkers of Responders and Nonresponders to First-Line Chemotherapy of Carboplatin and Paclitaxel

Conventional treatment for advanced ovarian cancer is an initial debulking surgery followed by chemotherapy combination of carboplatin and paclitaxel. Despite initial high response, three-fourths of these women experience disease recurrence with a dismal prognosis. Patients with advanced-stage ovarian cancer who underwent cytoreductive surgery were enrolled and tissue samples were collected. Post surgery, these patients were started on chemotherapy and followed up till the end of the cycle. Fluorescence-based differential in-gel expression coupled with mass spectrometric analysis was used for discovery phase of experiments, and real-time polymerase chain reaction, Western blotting, and pathway analysis were performed for expression and functional validation of differentially expressed proteins. While aldehyde reductase, hnRNP, cyclophilin A, heat shock protein-27, and actin are upregulated in responders, prohibitin, enoyl-coA hydratase, peroxiredoxin, and fibrin-β are upregulated in the nonresponders. The expressions of some of these proteins correlated with increased apoptotic activity in responders and decreased apoptotic activity in nonresponders. Therefore, the proteins qualify as potential biomarkers to predict chemotherapy response.

Gynaecological and other health problems of postmenopausal women and their health seeking behaviour in rural Terai, Nepal

Background: There is very few data available in menopausal study done in Nepal.   The data is even less on the various gynecological and medical problems postmenopausal women are suffering from. This study was done in Duhabi area, a community in Eastern Nepal, around the Comprehensive Health Service area of a   community hospital under B.P Koirala Institute of Health Sciences.Objective: This study was done to document the various gynecological problems among the postmenopausal   women and their relation with the socio-demographic characteristics.Methods: By using specific questionnaire, 234 post-menopausal women were   interviewed regarding menopausal symptoms, other gynaecological problems and   medical problems and their health seeking behaviour. Results: Our study showed   that the most common symptoms among the post-menopausal women were loss of libido (53%) and hot flushes (41.5%). Other noted symptoms found were vaginal   dryness (29.1%) and excessive vaginal bleeding (14.5%). The most common urinary symptoms were urgency (34.2%), dysuria (17.1%) and incontinence (17.1%). Uterine prolapse was reported by 6.4% of respondents. The most common medical condition seen in our study was low back ache (70.1%). Despite majority (62%) seeking medical treatment for their symptoms only 1.7% of the respondents were using hormone replacement therapy.Conclusion: The prevalence of gynaecological problems among the post-menopausal women was high in our study with the main symptoms of loss of libido and hot flushes. Majority of women with postmenopausal   symptoms sought medical care for their problems.   Health Renaissance 2014;12(2): pp: 87-91

Effect of organic carbon chemistry on sorption of atrazine and metsulfuron-methyl as determined by (13)C-NMR and IR spectroscopy

Soil organic matter (SOM) content is the major soil component affecting pesticide sorption. However, recent studies have highlighted the fact that it is not the total carbon content of the organic matter, but its chemical structure which have a profound effect on the pesticide's sorption. In the present study, sorption of atrazine and metsulfuron-methyl herbicides was studied in four SOM fractions viz. commercial humic acid, commercial lignin, as well as humic acid and humin extracted from a compost. Sorption data was fitted to the Freundlich adsorption equation. In general, the Freundlich slope (1/n) values for both the herbicides were <1. Except for atrazine sorption on commercial humic acid, metsulfuron-methyl was more sorbed. Desorption results suggested that atrazine was more desorbed than metsulfuron-methyl. Lignin, which showed least sorption of both the herbicides, showed minimum desorption. Sorption of atrazine was best positively correlated with the alkyl carbon (adjusted R (2) = 0.748) and carbonyl carbon (adjusted R (2) = 0.498) but, their effect was statistically nonsignificant (P = 0.05). Metsulfuron-methyl sorption showed best positive correlation with carbonyl carbon (adjusted R (2) = 0.960; P = 0.05) content. Sorption of both the herbicides showed negative correlation with O/N-alkyl carbon. Correlation of herbicide's sorption with alkyl and carbonyl carbon content of SOM fractions suggested their contribution towards herbicide sorption. But, sorption of metsulfuron-methyl, relatively more polar than atrazine, was mainly governed by the polar groups in SOM. IR spectra showed that H-bonds and charge-transfer bonds between SOM fraction and herbicides probably operated as mechanisms of adsorption.

Hypoxia-Induced Inflammatory Chemokines in Subjects with a History of High-Altitude Pulmonary Edema

High altitude hypoxia is known to induce an inflammatory response in immune cells. Hypoxia induced inflammatory chemokines may contribute to the development of high altitude pulmonary edema (HAPE) by causing damage to the lung endothelial cells and thereby capillary leakage. In the present study, we were interested to know whether chronic inflammation may contribute to HAPE susceptibility. We examined the serum levels of macrophage inflammatory protein-1α (MIP-1α), monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 in group (1) HAPE Susceptible subjects (n = 20) who had past history of HAPE and group (2) Control (n = 18) consist of subjects who had stayed at high altitude for 2 years without any history of HAPE. The data obtained confirmed that circulating MCP-1, MIP-1α were significantly upregulated in HAPE-S individuals as compared to the controls suggestive of chronic inflammation. However, it is not certain whether chronic inflammation is cause or consequence of previous episode of HAPE. The moderate systemic increase of these inflammatory markers may reflect considerable local inflammation. The existence of enhanced level of inflammatory chemokines found in this study support the hypothesis that subjects with past history of HAPE have higher baseline chronic inflammation which may contribute to HAPE susceptibility.

Development of an automated ballast water treatment verification system utilizing fluorescein diacetate hydrolysis as a measure of treatment efficacy

Methods for verifying ballast water treatments in foreign vessels are needed to protect the Great Lakes from the discharge of live non-native organisms or pathogens. A prototype automated viability test system using fluorescein diacetate (FDA), a membrane permeable fluorogen, to differentiate live from dead bacteria and algae is described. The automated fluorescence intensity detection device (AFIDD) captures cultured algae or organisms in Detroit River water (simulated ballast water) on 0.2 μm filters, backwashes them from the filter into a cuvette with buffer and FDA for subsequent fluorescence intensity measurements, and washes the filters with sterile water for serial automated reuse. Preliminary manual versions of these procedures were also tested. Tests of various buffers determined N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N,N-Bis(2-hydroxyethyl)taurine (BES) and 3-(N-morpholino)propanesulfonic acid (MOPS) at pH 7.0 to be the best buffers, causing the least spontaneous FDA breakdown without inhibiting enzymatic activity. Fluorescence in the presence of live organisms increased linearly over time, and the rate of increase was dependent on the sample concentration. Following simulated ballast water treatments with heat or chlorine, the fluorescence produced by Detroit River samples decreased to near control (sterile water) levels. Automated measurements of FDA hydrolysis with a reusable filter backwash system should be applicable to near real-time remote-controlled monitoring of live organisms in ballast water.

Adsorption and leaching behaviour of bispyribac-sodium in soils

Adsorption-desorption of the herbicide bispyribac-sodium was studied in four Indian soil types. Bispyribac-sodium was poorly adsorbed in the four soils and adsorption decreased with an increase in the herbicide concentration in solution. Freundlich adsorption coefficient (Kf) values for bispyribac-sodium ranged between 0.37 and 0.87. Slope (1/n) values varied from 0.2 to 0.31 suggesting that bispyribac-sodium adsorption was highly dependent on its initial concentration in solution. Bispyribac-sodium adsorption showed a positive correlation with soil pH (r = 0.809) and clay content (r = 0.699) while no correlation was observed with the organic carbon (r = 0.063) content. Sorbed herbicide was completely desorbed during a single desorption step suggesting that the herbicide was bound by weak adsorptive forces. Leaching studies of herbicide in soil 1 packed column indicated complete loss of soil applied herbicide under a simulated rainfall equivalent to 162 mm.

A comparative immunological analysis of CoCl2 treated cells with in vitro hypoxic exposure

The hypoxic preconditioning of mammalian cells has been shown to have beneficial effects against hypoxic injuries. However, very little information is available on the comparative analysis of immunological responses to hypoxic and hypoxia mimetic exposure. Therefore, in the present study, mouse peritoneal macrophages and splenocytes were subjected to hypoxia exposure (0.5 % O2) and hypoxia mimetic Cobalt chloride (CoCl2) treatment to evaluate their effect on immune response and delineate the underlying signaling mechanisms. The results obtained indicated that super oxide generation increased while TLR4 expression and cell surface markers like CD25, CD40 and CD69 were suppressed in both the treatments as compared to normoxia. Cobalt chloride treatment increased NF-κB expression, nitric oxide (NO) and iNOS expression, cytokines TNF-α and IL-6 as compared to hypoxia exposure. Our study showed that CoCl2 stabilizes HIF-1α to create hypoxia like conditions but it mainly influences the inflammatory response via NF-κB signaling pathway by skewing the production of proinflammatory molecules like TNF-α, IL-6 and NO.

Influence of boron addition to Ti-13Zr-13Nb alloy on MG63 osteoblast cell viability and protein adsorption

Cell proliferation, cell morphology and protein adsorption on near β-type Ti-13Zr-13Nb (TZN) alloy and Ti-13Zr-13Nb-0.5B (TZNB) composite have been investigated and compared to evaluate the effect of boron addition which has been added to the Ti alloy to improve their poor tribological properties by forming in situ TiB precipitates. MG63 cell proliferation on substrates with different chemistry but the same topography was compared. The MTT assay test showed that the cell viability on the TZN alloy was higher than the boron containing TZNB composite after 36 h of incubation and the difference was pronounced after 7 days. However, both the materials showed substantially higher cell attachment than the control (polystyrene). For the same period of incubation in fetal bovine serum (FBS), the amount of protein adsorbed on the surface of boron free TZN samples was higher than that in the case of boron containing TZNB composite. The presence of boron in the TZN alloy influenced protein adsorption and cell response and they are lower in TZNB than in TZN as a result of the associated difference in chemical characteristics.

Rhodiola inhibits dengue virus multiplication by inducing innate immune response genes RIG-I, MDA5 and ISG in human monocytes

Recognition of virus infection by retinoic acid-inducible gene (RIG) I and melanoma differentiation-associated protein (MDA) 5, which are RNA helicases, and interferon-stimulated gene (ISG) 15 activates cascades of signal transduction pathways leading to production of type I interferons and proinflammatory cytokines that orchestrate the elimination of the viruses. However, it has been demonstrated that RNA-helicase-mediated innate immunity plays an essential role in defending the host from infection. In our efforts to identify plant-derived antivirals that selectively enhance ISG- and RNA-helicase-mediated antiviral immune responses, we identified a plant, rhodiola, that significantly promoted ISG, RIG-I and MDA 5 gene expression and an antiviral immune response against dengue virus (DENV) infection. Rhodiola induced interferon (IFN) β and other cytokines, including IL-1β, TNF-α, IL-6 and IL-8, in infected cells. It was also found that rhodiola upregulated phosphorylated eIF-2α, PKR and NF-kB in infected cells. In addition, the number of NK cells was also increased by rhodiola treatment in dengue-virus-infected human PBMCs. Treatment with a crude extract of rhodiola (RAE) resulted in effects in the 20 % range, which is similar to the magnitude of the same effects observed in DENV infections. Taken together, our results imply that rhodiola induces pharmacological modulation of RIG-I, MDA 5 and ISG signal transduction pathways in favor of the induction of a beneficial antiviral immune response against dengue virus, which can be a novel therapeutic strategy for management of infection.

Delineation of the Structural Elements of Oriental Liver Fluke PLA2 Isoforms for Potent Drug Designing

Clonorchis sinensis or the Chinese liver fluke is one of the most prevalent parasites affecting a major population in the oriental countries. The parasite lacks lipid generating mechanisms but is exposed to fatty acid rich bile in the liver. A secretory phospholipase A2, an enzyme that breaks down complex lipids, is important for the growth of the parasite. The enzyme is also implicated in the pathogenesis leading up to the hepatic fibrosis and its complications including cancer. The five isoforms of this particular enzyme from the parasite therefore qualify as potential drug targets. In this study, a detailed structural and ligand binding analysis of the isoforms has been done by modeling. The overall three dimensional structures of the isoforms are well conserved with three helices and a β-wing stabilized by four disulfide bonds. There are characteristic differences at the calcium binding loop, hydrophobic channel and the C-terminal domain that can potentially be exploited for drug binding. But the most significant feature pertains to the catalytic site where the isoforms exhibit three variations of either a histidine-aspartate-tyrosine or histidine-glutamate-tyrosine or histidine-aspartate-phenylalanine. Molecular docking studies show that isoform specific residues and their conformations in the substrate binding hydrophobic channel make unique interactions with certain inhibitor molecules resulting in a perfect tight fit. The proposed ligand molecules have a predicted affinity in micro-molar to nano-molar range. Interestingly, few of the ligand binding interaction patterns is in accordance to the phylogenetic studies to thereby establish the usefulness of evolutionary mechanisms in aiding ligand design. The molecular diversity of the parasitic PLA2 described in this study provides a platform for personalized medicine in the therapeutics of clonorchiasis.

Potential pharmacokinetic role of organic cation transporters in modulating the transcorneal penetration of its substrates administered topically

PURPOSE

We hypothesize organic cation transporters (OCT) may have a potential role in determining the pharmacokinetics and toxicity of organic cation drugs applied topically. Hence, in the present in vivo study, we attempted to evaluate the role of OCT in modulating the transport of its substrates after topical application.

METHODS

New Zealand albino rabbits of either sex were used. Transcorneal penetration of OCT substrates tetraethylammonium and metformin after single instillation was evaluated in the absence and presence of OCT blockers (quinidine and atropine). Aqueous humor (AH) samples were collected through paracentesis amounting to 70-100 μl under topical anesthesia at various time intervals. The samples were subjected for estimation of both substrate as well as blocker concentrations using liquid chromatography mass spectrometry.

RESULTS

Topical pre-treatment (30 min before substrate) of OCT blockers significantly decreased the transcorneal penetration of OCT substrates after single topical administration. The levels of blockers reaching AH in the presence of substrates were also modulated at 60 min after its administration as compared with its control.

CONCLUSION

OCT are functionally active in the uptake of their substrates from tear to AH. Therefore, OCT in the corneal epithelium may be positioned from apical to basolateral. When administering their substrates/blockers topically, both may be competing for OCT for their uptake across the cornea, thereby decreasing the corneal penetration. Hence OCT can have a potential pharmacokinetic role in modulating the ocular bioavailability of their substrates administered topically, which are used as ocular therapeutics.

Hypoxic Stress Induced TREM-1 and Inflammatory Chemokines in Human Peripheral Blood Mononuclear Cells

Hypoxia is a condition of low pO2, which creates a unique microenvironment affecting cell phenotype and subsequent immune response generation. Little is known about the impact of hypoxia on the phenotypic expression of NK cell, TREM-1, TLR-4 and inflammatory chemokines. In the present study we have determined the frequency of peripheral blood populations of CD16/CD56 (NK Cells) expressing cells, presence of activation marker CD354 (TREM-1), Toll like receptor (CD 284) on the cell surface and chemokines IL-8 and RANTES in the cellular supernatant of normoxia and hypoxia exposed cells by flow cytometry. GRP-78 expression was determined by reverse transcriptase polymerase chain reaction. The blood was collected from healthy individuals and exposed to normoxic and hypoxic (0.5 %) environment for 24 h. The percentage of NK cells (CD 16/56) was marginally up regulated while TLR-4 expression was diminished in hypoxia exposed cells as compare to the normoxic cells. TREM-1 expression was significantly up-regulated (p < 0.05) in hypoxia as compared to the normoxic control. In addition when monocytic cell line THP-1 was exposed to 0.5 % hypoxia for 24 h, TLR4 expression was significantly decreased in hypoxic cells as compared to normoxic cells. Furthermore, GRP-78 mRNA expression was also upregulated by hypoxia or LPS exposure. These events are paralleled by strengthening up-regulation of the chemokines IL-8 and RANTES an otherwise necessary event for the chemotaxis of the neutrophils and macrophages to the inflammatory site. In conclusion, this study provides a novel insight into the mechanism linking low oxygen tension to the regulation of immune and inflammatory responses, leading to new perspectives of the role of hypoxia in programming immune cell functions.

Sugar partitioning in sprouting lateral bud and shoot development of sugarcane

Sugarcane is a leading energy crop of the world due to its ability to capitulate high sucrose. To understand the mechanism associated with shoot establishment from the lateral bud of sugarcane setts, at the time of germination, we established shoots and these shoots were incubated in total darkness and dark/light regime. The concentration of sugars (sucrose and hexoses) and activities of sugar metabolizing enzymes were measured from 0 to 21 days with 7 days intervals during shoot establishment using sugarcane cultivar CoS 97264. A decrease in sucrose concentration and increase in hexoses level was observed in intermodal tissues whereas in the shoots, the level of both sucrose and hexoses increased continuously during shoot establishment. During 0-21 days shooting period, the dry mass of internodes declined by 20 and 25% in plants incubated in dark/light and darkness respectively. All invertases, soluble acid invertase, neutral invertase and cell wall bound invertase were expressed with almost similar pattern in both the intermodal tissues and the shoots. The activity of enzyme sucrose synthase, measured within first 10 days of shooting in both types of tissues, appeared to be higher particularly in sugar breakdown direction. In the shoots, slight increase in sucrose synthase activity in sucrose synthesis direction was observed throughout shooting period in the shoots. The results suggest that sucrose is the main substrate used during shoot establishment and that shoot establishment period is characterized by increased activities of invertases and sucrose synthase and increased level of hexoses in the shoots.

Heart rate variabilty changes during first week of acclimatization to 3500 m altitude in Indian military personnel

Acute exposure to hypobaric hypoxia induces the changes in autonomic control of heart rate. Due to emergencies or war like conditions, rapid deployment of Indian military personnel into high altitude frequently occurs. Rapid deployment to high altitude soldiers are at risk of developing high altitude sickness. The present study was conducted to evaluate the acute exposure to high altitude hypobaric hypoxia (3500 m altitude) on the autonomic nervous control of heart rate in Indian military personnel during first week of acclimatization Indices of heart rate variability (viz; R-R interval, total power, low frequency, high frequency, ratio of low to high frequency) and pulse arterial oxygen saturation were measured at sea level and 3500m altitude. Power spectrum of heart rate variability was quantified by low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.5 Hz) widths. The ratio of LF to HF was also assessed as an index of the sympathovagal balance. Mean R-R interval decreased significantly on day 2 on induction to altitude which tended to increase on day 5. Total power (TP) decreased high altitude and tended to recover within a week. Both HF and LF power showed decrement at 3500m in comparison to sea level. The ratio of LF to HF (LF/HF) at 3500m was significantly higher at 3500m. SpO2 values decreased significantly (P < 0.05) at high altitude on day-2 which increased on day-5. We conclude that autonomic control of the heart rate measured by heart rate variability was altered on acute induction to 3500m which showed a significant decrease in parasympathetic tone and increase in sympathetic tone, then acclimatization seems to be characterized by progressive shift toward a higher parasympathetic tone.

Corrosion behaviour of heat treated boron free and boron containing Ti-13Zr-13Nb (wt%) alloy in simulated body fluid

The corrosion behaviour of heat treated Ti-13Zr-13Nb (TZN) and Ti-13Zr-13Nb-0.5B (TZNB) alloys in Hank's solution has been investigated. The microstructure of the heat treated TZN alloy consisted of α, β or martensite. Addition of boron to TZN alloy led to the formation of dispersed TiB particles and modification of microstructure. In general, the furnace cooled TZN sample showed lower corrosion potential (E(corr)) than the air cooled sample. Aging of water quenched samples decreased the E(corr) value. The passive current density of TZN samples varied within a narrow range. Presence of boron in TZN alloy decreased the corrosion potential and substantially increased the passive current density. Results showed that boron deteriorated the corrosion resistance of TZN alloy.

Functional analysis of sucrose phosphate synthase (SPS) and sucrose synthase (SS) in sugarcane (Saccharum) cultivars

Sucrose phosphate synthase (SPS; EC 2.4.1.14) and sucrose synthase (SS; EC 2.4.1.13) are key enzymes in the synthesis and breakdown of sucrose in sugarcane. The activities of internodal SPS and SS, as well as transcript expression were determined using semi-quantitative RT-PCR at different developmental stages of high and low sucrose accumulating sugarcane cultivars. SPS activity and transcript expression was higher in mature internodes compared with immature internodes in all the studied cultivars. However, high sugar cultivars showed increased transcript expression and enzyme activity of SPS compared to low sugar cultivars at all developmental stages. SS activity was higher in immature internodes than in mature internodes in all cultivars; SS transcript expression showed a similar pattern. Our studies demonstrate that SPS activity was positively correlated with sucrose and negatively correlated with hexose sugars. However, SS activity was negatively correlated with sucrose and positively correlated with hexose sugars. The present study opens the possibility for improvement of sugarcane cultivars by increasing expression of the respective enzymes using transgene technology.

Effect of fluoroquinolones on the expression of matrix metalloproteinase in debrided cornea of rats

Matrix metalloproteinases (MMPs) are implicated in regenerative and healing processes in corneal injuries. Based upon reports that topical fluoroquinolones (FQs) may cause perforations during corneal healing by modulating MMPs, this study evaluated the comparative effects of commercially available FQs eye drops on the expression of MMP-2 and MMP-9 in the cornea after ethanol injury. Uniform corneal epithelial defects were created using 70% ethanol in the right eye of the rats (n = 6). The groups studied were (I) sham, (II) normal saline with benzalkonium chloride (NS-BKC), (III) norfloxacin 0.3%, (IV) ciprofloxacin 0.3%, (V) lomefloxacin 0.3%, (VI) sparfloxacin 0.3%, (VII) gatifloxacin 0.3%, and (VIII) moxifloxacin 0.5%. Each treatment was instilled six times/day up to 48 h and rats were sacrificed using excess of anesthesia. The corneas were excised to study the expression of MMP-2 and MMP-9 using gelatin zymography and real-time PCR. All the FQs significantly increased the expression of MMP-2 and MMP-9 as compared to the sham and NS-BKC-treated group. NS-BKC did not show a significant effect on MMPs expression compared to the sham group. Among the studied FQs, ciprofloxacin was observed to exhibit maximal induction of MMP-2 and MMP-9, whereas lomefloxacin exhibited an equivocal effect on both MMP-2 and MMP-9 expression. Findings of the present study demonstrate that topical application of FQs may induce the expression of MMP-2 and MMP-9 in debrided corneal epithelium and, therefore, may delay corneal wound healing. Thus, it can be concluded that selecting a FQ for ophthalmic use having minimal effect on MMPs may impact wound healing in injured or vulnerable cornea.

Emergence of Virulence to Sr25 of Puccinia graminis f. sp. tritici on Wheat in India

Stem (black) rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks. & Henn., is one of the most destructive diseases of wheat. It could be controlled through introgression of race-specific resistance genes. However, such kind of resistance is mostly short lived due to emergence of new virulences. For example, resistance genes Sr11, Sr24, Sr30, and Sr31 are no longer effective (2,4). Detection of new virulences has remained vital in the evaluation and identification of new sources of resistance. We report here the detection of virulence to Sr25, a gene from Thinopyrum elongatum (4), which had been effective or partially effective against stem rust worldwide, including race Ug99 (TTKSK) (4). A stem rust isolate collected in 2006 from Karnataka (southern India) produced susceptible reactions (infection type [IT] 3+ to 4) on the primary leaves of differential genotype 'Agatha' carrying Sr25 and susceptible check 'Agra Local' at 22 ± 2°C. To verify virulence to Sr25, single-pustule isolates from this sample were inoculated onto seedlings of 'Agrus', 'Agatha', 'RL6040' ('Thatcher' + Sr25), 'Superseri#1', 'Wheatear', and 'Morocco' + Sr25 (obtained from CIMMYT), which all carry Sr25. All these accessions were found susceptible (IT 3+ to 4) to this isolate, except Wheatear which expressed resistance (IT ;1), indicating the presence of additional gene(s). These genotypes are resistant (ITs ;1 to 2+) to Sr25-avirulent pathotypes. The new pathotype is avirulent to Sr11, 13, 14, 21, 22, 23, 24, 26, 27, 29, 31, 32, 33, 35, 37, 38, 39, 40, 43, and Tmp and virulent to Sr5, 6, 7a, 7b, 8a, 9a, 9b, 9d, 9e, 9f, 9g, 10, 12, 15, 16, 17, 18, 19, 20, 25, 28, 30, 34, 36, 42, Wld-1, and Gt at 22 ± 2°C. This pathotype has been designated as 58G13-3 and PKTSC according to the Indian nomenclature (1) and the North American system (3), respectively. It represents race 40 based on Stakman's differentials. It may have arisen from race 40 through mutation. The type culture of the pathotype has been added to the culture collection at Flowerdale, Shimla. Interestingly, 'Festiguay' (Sr30) was found resistant to this pathotype, indicating the presence of additional gene(s), whereas 'Webster' (Sr30) was susceptible. Adult plants of Agrus, Agatha, RL6040, Superseri#1, and Morocco+Sr25 also were susceptible, producing 20S to 60S responses. Sr25-avirulent pathotype 62G29 produced a TR (flecking in traces) response on these lines except Morocco + Sr25 that showed 20 to 40MR (moderately resistant) responses. In the same study however, adult plants of Thatcher showed a resistant reaction (10R to MR) at low (16 ± 2°C) and susceptible (20S) at high (22 ± 2°C) temperatures. Agatha and RL6040, having Thatcher as one of the parents, had similar responses. The detection of Sr25 virulence is significant since Sr25 is an important gene to be targeted for breeding wheat cultivars resistant to Ug99. We should use either adult plant resistance and/or pyramiding two or more genes for seedling resistance to enhance the field life of wheat cultivars. References: (1) P. Bahadur et al. Proc. Indian Acad. Sci. 95:29, 1985. (2) S. C. Bhardwaj et al. J. Wheat Res. 1:51, 2007. (3) Y. Jin et al. Plant Dis. 92:923, 2008. (4) R. P. Singh et al. CAB Rev. No. 054:1, 2006.

Acetyl-l-carnitine (ALCAR) prevents hypobaric hypoxia-induced spatial memory impairment through extracellular related kinase-mediated nuclear factor erythroid 2-related factor 2 phosphorylation

Exposure to hypobaric hypoxia, a condition involving decreased availability of oxygen is known to be associated with oxidative stress, neurodegeneration and memory impairment. The multifactorial response of the brain and the complex signaling pathways involved therewith limits the therapeutic efficacy of several antioxidants in ameliorating hypobaric hypoxia-induced memory impairment. The present study was therefore aimed at investigating the potential of acetyl-l-carnitine (ALCAR), a known antioxidant that has been reported to augment neurotrophin-mediated survival mechanisms, in ameliorating hypoxia-induced neurodegeneration and memory impairment. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor involved in the cellular defense mechanism against oxidative stress related to brain injury and neurological disorders. The study was designed to understand the mechanisms involving Nrf2 stabilization following exposure to hypobaric hypoxia. The results displayed reference memory impairment in Sprague-Dawley rats exposed to hypobaric hypoxia (7620 m) for 14 consecutive days which however improved on administration of ALCAR during hypoxic exposure. The study also revealed Nrf2 regulated augmented antioxidant response on administration of ALCAR which was through a novel tyrosine kinase A (TrkA) receptor-mediated mechanism. A decrease in free radical generation, lipid peroxidation and protein oxidation was also observed along with a concomitant increase in thioredoxin and reduced glutathione levels on administration of ALCAR during exposure to hypobaric hypoxia. The present study therefore reveals the therapeutic potential of ALCAR under conditions of hypobaric hypoxia and elucidates a novel mechanism of action of the drug.

Changing spectrum of antibiotic sensitivity in enteric fever

AIMS AND OBJECTIVES

The study was designed to analyze clinical profile and Antibiotic sensitivity pattern in case of culture positive typhoid fever and compare response of quinolones in vitro and in vivo.

METHODOLOGY

Forty eight cases of culture positive enteric fever presented in outpatient and emergency department of Kathmandu Medical College, Sinamangal, and Kathmandu were included in the study. Sensitivity pattern of isolates from blood culture was done by antibiotic disc diffusion method and this was compared with clinical response.

RESULTS

Response was based on Fever Clearance Time (FCT) and it was found that mean FCT was 3.58 days with standard deviation of 1.84 .Comparison was made separately for FCT >or=5 days and it was found that vomiting as the symptom and stool occult blood positive as the investigation to predict prolong FCT. Nalidixic acid as compared with other quinolones showed that other quinolones (ciprofloxacin, ofloxacin) are effective even in Nalidixic acid resistant cases when FCT was taken as the criteria of response, and it doesn't include the relapse rate.

CONCLUSION

Enteric fever is one of the leading causes of fever in Nepal. The diagnosis in most of the cases is done empirically by clinical features, but culture and sensitivity of blood or bone marrow is the gold standard way of diagnosis and providing treatment. The antibiotic sensitivity pattern is changing and resistance cases are emerging with indiscriminate use of drugs.

N-acetyl cysteine supplementation prevents impairment of spatial working memory functions in rats following exposure to hypobaric hypoxia

Exposure to high altitude (HA), especially extreme altitude, is associated with impairment of cognitive functions including memory and increased oxidative stress. However, the underlying mechanisms involved are not well understood. It is hypothesized that HA induced oxidative stress may be one of the factors underlying hypoxia induced memory impairment. The aim of the present study was to investigate the effect of hypobaric hypoxia (HH) on spatial working and reference memory functions, oxidative stress markers in rats and effect of supplementation of N-acetyl cysteine (NAC). The rats were divided into four groups. Group I served as normoxic (n=6), Group II served as hypoxic (n=6), Group III as hypoxia group treated with NAC (n=6) and Group IV served as normoxic group treated with NAC (n=6). Group II & III were exposed to HH for 3 days equivalent to 6100 m and received oral NAC supplementation (750 mg/kg) daily. Rats from all the groups were trained in Morris Water Maze (MWM) task for 8 consecutive days. Spatial working and reference memory were tested immediately after the termination of HH and then the rats were sacrificed for estimation of oxidative stress markers in hippocampus. Rats displayed significant deficits in spatial working memory, and increased oxidative stress along with decrease in antioxidant status on hypoxic exposure. Supplementation with NAC in hypoxia-exposed group improved spatial memory performance, and decreased oxidative stress. These findings indicate that hypoxic exposure is associated with increased oxidative stress, which may have caused memory deficit in rats exposed to simulated HA.