Bioremediation and bioscavenging for elimination of organophosphorus threats: An approach using enzymatic advancements

Organophosphorus compounds (OP) are highly toxic pesticides and nerve agents widely used in agriculture and chemical warfare. The extensive use of these chemicals has severe environmental implications, such as contamination of soil, water bodies, and food chains, thus endangering ecosystems and biodiversity. Plants absorb pesticide residues, which then enter the food chain and accumulate in the body fat of both humans and animals. Numerous human cases of OP poisoning have been linked to both acute and long-term exposure to these toxic OP compounds. These compounds inhibit the action of the acetylcholinesterase enzyme (AChE) by phosphorylation, which prevents the breakdown of acetylcholine (ACh) neurotransmitter into choline and acetate. Thus, it becomes vital to cleanse the environment from these chemicals utilizing various physical, chemical, and biological methods. Biological methods encompassing bioremediation using immobilized microbes and enzymes have emerged as environment-friendly and cost-effective approaches for pesticide removal. Cell/enzyme immobilized systems offer higher stability, reusability, and ease of product recovery, making them ideal tools for OP bioremediation. Interestingly, enzymatic bioscavengers (stoichiometric, pseudo-catalytic, and catalytic) play a vital role in detoxifying pesticides from the human body. Catalytic bioscavenging enzymes such as Organophosphate Hydrolase, Organophosphorus acid anhydrolase, and Paraoxonase 1 show high degradation efficiency within the animal body as well as in the environment. Moreover, these enzymes can also be employed to decontaminate pesticides from food, ensuring food safety and thus minimizing human exposure. This review aims to provide insights to potential collaborators in research organizations, government bodies, and industries to bring advancements in the field of bioremediation and bioscavenging technologies for the mitigation of OP-induced health hazards.

Recombinant Organophosphorus acid anhydrolase (OPAA) enzyme-carbon quantum dot (CQDs)-immobilized thin film biosensors for the specific detection of Ethyl Paraoxon and Methyl Parathion in water resources

Organophosphates pesticide (OP) toxicity through water resources is a large concern globally among all the emerging pollutants. Detection of OPs is a challenge which needs to be addressed considering the hazardous effects on the health of human beings. In the current research thin film biosensors of recombinant, Organophosphorus acid anhydrolase (OPAA) enzyme along with carbon quantum dots (CQDs) immobilized in thin films were developed. OPAA-CQDs thin film biosensors were used for the specific detection of two OPs Ethyl Paraoxon (EP) and Methyl Parathion (MP) in river water and household water supply. Recombinant OPAA enzyme was expressed in E. Coli, purified and immobilized on the CQD containing chitosan thin films. The CQDs used for this purpose were developed by a one-pot hydrothermal method from phthalic acid and Tri ethylene diamine. The properties of CQDs, OPAA and thin films were characterized using techniques like XPS, TEM, XRD, enzyme activity and CLSM measurements. Biosensing studies of EP and MP were performed by taking fluorescence measurements using a fiber optic spectrometer. The analytical parameters of biosensing were compared against an estimation carried out using the HPLC method. The biosensing performance indicates that the OPAA-CQDs thin film-based biosensors were able to detect both EP and MP in a range of 0-100 μM having a detection limit of 0.18 ppm/0.69 ppm for EP/MP, respectively with a response time of 5 min. The accuracy of estimation of EP/MP when spiked in water resources lie in the range of ∼100-102% which clearly indicates the OPAA-CQD based thin film biosensors can function as a point-of-use method for the detection of OP pesticides in complex water resources.

Outer membrane proteins and vesicles as promising vaccine candidates against Vibrio spp. infections

Indiscriminate use of antibiotics to treat bacterial infections has brought unmanageable antibiotic-resistant strains into existence. Vibrio spp. represents one such gram-negative enteric pathogenic group with more than 100 species, infecting humans and fish. The Vibrio spp. is demarcated into two groups, one that causes cholera and the other producing non-cholera or vibriosis infections. People who encounter contaminated water are at risk, but young children and pregnant women are the most vulnerable. Though controllable, Vibrio infection still necessitates the development of preventative measures, such as vaccinations, that can lessen the severity of the infection and reduce reliance on antibiotic use. With emerging multi-drug resistant strains, efforts are needed to develop newer vaccines, such as subunit-based or outer membrane vesicle-based. Thus, this review strives to bring together available information about Vibrio spp. outer membrane proteins and vesicles, encompassing their structure, function, and immunoprotective role.

Trends in ECT (Electroconvulsive Therapy) Utilization During Pregnancy and Post-Partum Period: National Inpatient Sample 2002-2015

Introduction

The use of Electroconvulsive therapy (ECT) during pregnancy and in the post-partum period is a critical decision for both providers and their patients. ECT utilization during this critical period needs to be better understood to assess the need and allocate resources for this valuable treatment option.

Objectives

1) To evaluates baseline characteristics and analyze ECT utilization trends for pregnant and post-partum patients hospitalized in the US. 2) To provide insight into ECT use among inpatient pregnant women with different age groups with various comorbid psychiatric disorders.

Methods

The study used the 2002-2015 National (Nationwide) Inpatient Sample (NIS) data. Descriptive statistical and trend analyses were conducted to evaluate data.

Results

A study found that a total of 924 pregnancy-related hospitalizations required ECT treatment; 92.2% of these ECTs were conducted in urban hospitals. The mean age of women was 30.3 years, and the majority (71%) were of the White race. Mood disorders (major depressive disorder- 51.9% and bipolar disorder- 37.9%) accounted for the most common comorbid psychiatric illnesses. The payer source (Medicare/Medicaid vs. Private Insurance) was almost equal (47.9 vs. 46.8). Though not statistically significant, the trend analysis showed that the proportion of ECTs during pregnancy out of the total ECT performed for the year almost doubled (0.24% to 0.47%) from 2008 to 2015.

Conclusions

Though not statistically significant, the use of ECT in pregnant women has increased in 2015 compared to 2002. Results will help clinicians, policymakers, and various stakeholders to optimize ECT utilization, reimbursement and ultimately improve clinical outcomes.

Disclosure

No significant relationships.

Clonal Expansion of Stem/Progenitor Cells in Cancer, Fibrotic Diseases, and Atherosclerosis, and CD47 Protection of Pathogenic Cells

We proposed and demonstrated that myelogenous leukemia has a preleukemic phase. In the premalignant phase, normal hematopoietic stem cells (HSCs) gradually accumulate mutations leading to HSC clonal expansion, resulting in the emergence of leukemic stem cells (LSCs). Here, we show that preleukemic HSCs are the basis of clonal hematopoiesis, as well as late-onset blood diseases (chronic-phase chronic myeloid leukemia, myeloproliferative neoplasms, and myelodysplastic disease). The clones at some point each trigger surface expression of "eat me" signals for macrophages, and in the clones and their LSC progeny, this is countered by upregulation of "don't eat me" signals for macrophages such as CD47,opening the possibility of CD47-based therapies. We include evidence that similar processes result in fibroblast expansion in a variety of fibrotic diseases, and arterial smooth muscle clonal expansion is a basis of atherosclerosis, including upregulation of both "eat me" and "don't eat me" molecules on the pathogenic cells.

502 OUTCOMES OF HOSPITALISED PATIENTS WITH COVID-19 SIX MONTHS AFTER INDEX ADMISSION

Introduction

Early outcomes for hospitalised patients with covid-19, including admissions to critical care and mortality have been widely published. Less is known about the longer-term patient outcomes such as readmissions, deaths after discharge and level of care required on discharge.

Methods

Following an audit of 360 consecutive admissions of patients with covid-19 requiring level 1 inpatient care in spring 2020, we collated data about mortality, readmissions, and residential status for the same cohort at six months after index admission.

Results

The cohort had a median age of 78: 70% survived to discharge. Median length of stay was nine days (range 1–90). Of 252 patients discharged, a further 35 (14%) had died by six-month follow-up. 95 patients (38%) required at least one further hospital admission in the following six-month period. 40 (16%) of discharged patient required increased support, defined as new or increased package of care or an alternative interim or permanent change of residence. (Table 1). Table 1 emailed separately as will not transfer into this space Of the 40 patients requiring increased support on discharge, 7 (18%) died, 15 (38%) returned to their preadmission residential status, and 17 (43%) still required increased support.

Conclusions

Covid-19 has a high mortality rate in those admitted to hospital. Patients receiving level 1 care in hospital and surviving to discharge have a high risk of readmission or death in the following six-months. For those requiring increased support on discharge, the majority do not return to their pre-admission residential status.

Phytochemical Screening and Antifungal Activity of Samadera indica

Samadera indica plant is an antifungal and bitter plant spread all over India. The applications of NDDS in phytopharmaceuticals have been widely investigated and various commercial formulations of plants are available in the global market. The goal of nano drug delivery system of herbal extract is to reduce toxicity, to improve drug efficacy, to improve better therapeutic effect, etc. Nanomicelles of samadera indica were successfully prepared by solvent evaporation method and studied various parameters such as Preliminary phytochemical screening, Scanning electron microscopy, and antifungal study. In present methodology, it was concluded that the Nanomicelles of methanolic extract of samadera indica plant was successfully prepared. It was safe and non- toxic. Plant extract contained flavonoids, triterpenes, and alkaloids which is responsible for antifungal activity. This research work concludes that the samadera indica is used as antioxidant, antimicrobial as well as antifungal compound. Novel drug delivery system is a advanced technology for delivering the drug with their so many advantages. Nanomicelles is an excellent pharmaceutical carriers by using bioactive constituents of plant having no side effects, effective formulation for various diseases especially in case of skin diseases. Novel formulation enhanced the topical drug delivery system of Samadera indica in order to treat skin infections was developed.

Analytical assessment of maize kernels for Fe, Zn, and β-carotene dense cultivars with low phytate contents

The present paper reports that significant genetic variability was evident in Fe, Zn, β-carotene, and phytic acid (phytate, PA) contents in a set of 39 diverse maize genotypes collected from maize breeding programme of hill agriculture, India. The Fe, Zn, β-carotene, and PA concentrations were found to be in the range 19.31–50.64 mg kg−1, 12.60–37.18 mg kg−1, 0.17–8.27 µg g−1, and 6.59–7.13 g kg−1, respectively. The genotypes V335, V420, V393, V416, V414, V372, and V351 were identified to have higher concentration of β-carotene, Fe, and Zn but lower amount of PA. Possible availability of the minerals Fe and Zn was determined using molar ratio between PA as inhibitor and β-carotene as promoter for their absorption. The micronutrient molar ratio showed that Fe and Zn traits could be dependent of each other. Low R2 value revealed relation between β-carotene and kernel colour. The selected genotypes could be considered as potential sources of favourable genes for further breeding programs to develop micronutrient enriched maize cultivars.

Sex-specific aortic root anatomy in patients with bicuspid aortic valve undergoing TAVR in a Chinese cohort

Objectives

The aim of this study is to investigate the sex-specific aortic root anatomy in patients with bicuspid aortic valve (BAV).

Patients and methods

This retrospective study includes 73 consecutive patients with BAV who underwent CT evaluation before transcatheter aortic valve replacement (TAVR) between July 2013 and April 2017 in the Second Affiliated Hospital of Zhejiang University.

Result

The size of the annulus, diameter and height of the sinotubular junction (STJ), height of the coronary artery ostia, and dimension of the aorta were measured. Women had significantly smaller annulus parameters (mean diameter: 23.4 ± 1.8 vs. 26.1 ± 2.1 mm; area: 425.3 ± 59.4 vs. 527.4 ± 84.6 mm²; perimeter: 74.3 ± 5.2 vs. 83.2 ± 6.4 mm), and STJ diameter (29.7 ± 3.1 vs. 32.6 ± 4.5 mm) than men (p < 0.01 for all), even after adjustment for their smaller body surface area (BSA). Dimension of aorta and height of right coronary artery were also significantly smaller in women, although not when indexing for the BSA. The left ventricular ejection fraction of women is significantly higher than that of men before discharge (60.2 ± 9.7% vs. 53.7 ± 13.6%, p = 0.01). There were no differences between women and men in the all-cause 30-day and 1‑year mortality.

Conclusion

Women with BAV had smaller annulus and STJ diameter after indexing for BSA, reflecting a sex-specific difference. There were no differences in 30-day and 1‑year mortality between the two groups.

Electronic supplementary material

The online version of this article (10.1007/s00059-018-4740-0) contains supplementary material, which is available to authorized users.

New piperidine derivative DTPEP acts as dual-acting anti-breast cancer agent by targeting ERα and downregulating PI3K/Akt-PKCα leading to caspase-dependent apoptosis

OBJECTIVES

In our ongoing studies to develop ER targeting agents, we screened for dual-acting molecules with a hypothesis that a single molecule can also target both ER positive and negative groups of breast cancer.

MATERIALS AND METHODS

1-(2-(4-(Dibenzo[b,f]thiepin-10-yl)phenoxy)ethyl)piperidine (DTPEP) was synthesized and screened in both MCF-7 (ER+ve) and MDA-MB-231 (ER-ve) cells. Assays for analysis of cell cycle, ROS, apoptosis and MMP loss were carried out using flow cytometry. Its target was investigated using western blot, transactivation assay and RT-PCR. In vivo efficacy of DTPEP was validated in LA-7 syngeneic rat mammary tumour model.

RESULTS

Here, we report identification of dual-acting molecule DTPEP that downregualtes PI3K/Akt and PKCα expression, induces ROS and ROS-dependent apoptosis, loss of mitochondrial membrane potential, induces expression of caspase indicative of both intrinsic and extrinsic apoptosis in MCF-7 and MDA-MB-231 cells. In MCF-7 cells, DTPEP downregulates ERα expression and activation. In MDA-MB-231 cells, primary cellular target of DTPEP is not clearly known, but it downregualtes PI3K/Akt and PKCα expression. In vivo study showed regression of LA-7 syngeneic mammary tumour in SD rat.

CONCLUSIONS

We identified a new dual-acting anti-breast cancer molecules as a proof of concept which is capable of targeting both ER-positive and ER-negative breast cancer.

Acquired Constricting Band Syndrome

The superstitious beliefs of gaining a good fortune led to wearing rubber bands around the hand leading to the development of the constricting band syndrome. Acute compartment syndrome is a limb-threatening condition characterized by elevated interstitial pressure in a confined fascial compartment and if left untreated, it results in tissue necrosis, irreversible nerve and muscle injury and permanent functional impairment. We report a 46 years old male with history of wearing rubber hand on all his fingers, who presented late with gangrene and autoamputation.

45° sign switching of effective exchange bias due to competing anisotropies in fully epitaxial Co3FeN/MnN bilayers

We report an unusual angular-dependent exchange bias effect in ferromagnet/antiferromagnet bilayers, where both ferromagnet and antiferromagnet are epitaxially grown. Numerical model calculations predict an approximately 45° period for the sign switching of the exchange-bias field, depending on the ratio between magnetocrystalline anisotropy and exchange-coupling constant. The switching of the sign is indicative of a competition between a fourfold magnetocrystalline anisotropy of the ferromagnet and a unidirectional anisotropy field of the exchange coupling. This predicted unusual angular-dependent exchange bias and its magnetization switching process are confirmed by measurements on fully epitaxial Co₃FeN/MnN bilayers by longitudinal and transverse magneto-optic Kerr effect magnetometry. These results provide a deeper understanding of the exchange coupling phenomena in fully epitaxial bilayers with tailored materials and open up a complex switching energy landscape engineering by anisotropies.

Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI

We report the results of resonant magnetic XUV reflectivity experiments performed at the XUV free-electron laser FERMI. Circularly polarized XUV light with the photon energy tuned to the Fe M_2,3 edge is used to measure resonant magnetic reflectivities and the corresponding Q-resolved asymmetry of a Permalloy/Ta/Permalloy trilayer film. The asymmetry exhibits ultrafast changes on 240 fs time scales upon pumping with ultrashort IR laser pulses. Depending on the value of the wavevector transfer Q_z , we observe both decreasing and increasing values of the asymmetry parameter, which is attributed to ultrafast changes in the vertical spin and charge density profiles of the trilayer film.

Role and regulation of p27 in neuronal apoptosis

It is necessary for the cell-cycle machinery of neurons to be suppressed to promote differentiation and maintenance of their terminally differentiated state. Reactivation of the cell cycle in response to neurotoxic insults leads to neuronal cell death and some cell-cycle-related proteins contribute to the process. p27 kip1 (p27), an inhibitor of cyclin-dependent kinases, prevents unwarranted cyclin-dependent kinase activation. In this study, we have elucidated a novel mechanism via which p27 promotes apoptosis of neurons stimulated by neurotoxic amyloid peptide Aβ₄₂ (Amyloid β_1-42 peptide). Co-immunoprecipitation analysis revealed that p27 promotes interaction between Cyclin-dependent kinase 5 (Cdk5) and cyclin D1, which is induced by Aβ₄₂ in cortical neurons. As a result, Cdk5 is sequestered from its neuronal activator p35 resulting in kinase deactivation. The depletion of p27, which was achieved by specific siRNA, restored Cdk5/p35 interaction by preventing association between Cdk5 and cyclin D1 and also abrogated Aβ₄₂ induced apoptosis of cortical neurons. Furthermore, analysis of cell cycle markers suggested that p27 may play a role in Aβ₄₂ induced aberrant cell cycle progression of neurons, which may result in apoptosis_. These findings provide novel insights into how p27, which otherwise performs important neuronal functions, may become deleterious to neurons under neurotoxic conditions.

A mechanistic investigation of the bioavailability enhancing potential of lysergol, a novel bioenhancer, using curcumin

Lysergol (LYZ), a novel bioenhancer, has shown potential to enhance the bioavailability of curcumin.

Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow

A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed.

External validation of prognostic model of one-year mortality in patients requiring prolonged mechanical ventilation

BACKGROUND

External validation of prognostic model for one-year mortality in patients ventilated for 21 days or more. A measure that identifies patients who are at high risk of mortality after prolonged ventilation will help physicians communicate prognoses to patients or surrogate decision makers. Our objective was to validate a prognostic model developed by Carson et al in a different setting.

METHODS

An observational study was conducted from September 2002 to September 2007 in 30 beds Medical/Surgical Intensive Care Unit (ICU) at Mercy Fitzgerald Hospital (MFH) and 20 beds Medical/Surgical ICU at Mercy Philadelphia Hospital (MPH). One hundred and fifty medical and surgical patients requiring mechanical ventilation after acute illness for at least 21 days after initial intubation were enrolled.

RESULTS

One year mortality was 45.4%. Area under the receiver operating characteristic curve for three month mortality was 0.90 and for one year mortality was 0.92. For identifying patients who had ≥90% risk of death at 3 month had sensitivity of 40% and specificity of 95% and risk of death at 1 year had sensitivity of 70% and specificity of 99%. Four predictive variables, requirement of vasopressors, hemodalysis, platelet count ≤ 150 x 10 9/L and age ≥50 yrs can be used as a simple prognostic score that clearly identifies low-risk patients and high-risk patients.

CONCLUSIONS

Simple clinical variables measured on day 21 of mechanical ventilation can identify patients at highest and lowest risk of death from prolonged mechanical ventilation.

CoMFA and CoMSIA analysis of tetrahydroquinolines as potential antimalarial agents

Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were used on a dataset of compounds, some of them having been reported to inhibit Plasmodium falciparum protein, farnesyltransferase. The co-crystal structure of the lead molecule, BMS-214662 bound to Rat-PFT was used as a template. CoMFA yielded a good model, with r²(ncv) = 0.909, r²(cv) = 0.617 and was validated using an external set r²(pred) = 0.748). It compared favourably with CoMSIA. In the CoMFA model the steric and electrostatic fields exerted an almost equal influence on activity. The contour maps indicated the necessity for sterically large electropositive groups with electronegative tail to be present in these molecules for activity, and sterically large electronegative moieties on the sulfonamide linker. By incorporating these features some new compounds have been identified for further investigation.

Ab initio determination of geometries and vibrational characteristics of building blocks of organic superconductors: 4,5-Ethylenedithio-1,3-dithiole-2-thione, and 4,5-ethylenedithio-1,3-dithiole-2-one

RHF and DFT calculations were carried out to study the optimized molecular geometries and vibrational characteristics of the 4,5-ethylenedithio-1,3-dithiole-2-thione (EDT-DTT) and 4,5-ethylenedithio-1,3-dithiole-2-one (EDT-DTO) molecules and their radical cations and anions. It is found that the anionic radical of the EDT-DTO molecule is unstable. Both the neutral molecules and their radical cations have non-planar structures with C(2) symmetry while the radical anion of the EDT-DTT molecule has non-planar structure with C(1) symmetry. It is found that the most of the vibrational characteristics of the radicals are similar to their corresponding neutral molecules, however, for some of the modes significant changes are noticed. As a result of anionic radicalization of EDT-DTT, the IR intensity and Raman activity increase and Raman band becomes polarized for both the CH(2) twisting modes. Drastic enhancements in the Raman activity and reduced IR intensity are noticed for the C=S/O stretching mode in going from neutral molecules to their radical ions consistent with charge separation along this bond. The C=S and C=C stretching wavenumber changes are consistent with corresponding bond length changes in going from neutral to their radical ions.

Monocular visual loss due to herniation of gyrus rectus: A case report with review of literature

The authors present an unusual case of a polar mass in the frontal lobe of the brain, causing acute monocular visual loss in a 50-year-old woman with history of breast carcinoma treated with surgery, radiation and chemotherapy. Neuroimaging demonstrated herniation of the gyrus rectus into the suprasellar cistern resulting in compression of the anterior visual pathway.

Aluminum phosphide poisoning: effect of correction of severe metabolic acidosis on patient outcome

Forty patients of aluminum phosphide poisoning who were admitted to the ICU of Sir Sunder Lal Hospital, Banaras Hindu University, were studied. Restlessness, excessive thirst, shock, arrhythmias, tachypnoea, and severe metabolic acidosis were the common clinical findings. Only repeated and full correction with intravenous sodium bicarbonate was able to cope up with the severity and rapidity of acidosis. There was no significant change in blood pressure, pulse rate, and respiratory rate after full correction but gradually pulse and systolic blood pressure settled after ionotropic support in the survivors. There was significant improvement from 30.36% in the case when only half correction was done, as has been the common practice, to 57.5%, when full correction of metabolic acidosis was done.

Evaluation of intracranial space-occupying lesion with Tc99m-glucoheptonate brain single photon emission computed tomography in treatment-naïve patients

BACKGROUND

Glucoheptonate is a glucose analog with strong affinity for neoplastic brain tissues. Though extensively used as a tracer for detection of brain tumor recurrence, it's utility for characterization of intracranial lesions as neoplastic or otherwise has not been evaluated in treatment-naïve patients.

AIM

The study was conducted to determine if glucoheptonate has sufficient specificity for neoplastic lesions of brain so that it can be utilized as a single photon emission computed tomography (SPECT)-tracer for differentiating neoplastic intracranial lesions from non-neoplastic ones in treatment-naïve patients.

SETTINGS AND DESIGN

A cross-sectional analysis of treatment-naïve patients with intracranial space-occupying lesion done in a tertiary care hospital.

MATERIALS AND METHODS

Fifty-four consecutive patients with clinical and radiological features of space-occupying lesion were included in this study. Glucoheptonate brain SPECT was performed before any definitive therapeutic intervention. Histopathological verification of diagnosis was obtained in all cases.

STATISTICAL ANALYSIS USED

Descriptive statistics and student's 't' test.

RESULT

Increased glucoheptonate uptake over the site of radiological lesion was noted in 41 patients and no uptake was noticed in 13 patients. Histopathology of 12 out of the 13 glucoheptonate non-avid lesions turned out to be non-neoplastic lesion; however, one lesion was reported as a Grade-2 astrocytoma. Histology from all the glucoheptonate concentrating lesions was of mitotic pathology. The sensitivity, specificity and accuracy of glucoheptonate for neoplastic lesion was 97.6%, 100% and 98.1%.

CONCLUSIONS

Glucoheptonate has high degree of specificity for neoplastic tissues of brain and may be used as a tracer for SPECT study to differentiate neoplastic intracranial lesions from non-neoplastic ones.

Ab initio studies of molecular structures, conformers and vibrational spectra of heterocyclic organics: I. Nicotinamide and its N-oxide

FTIR spectra of nicotinamide and its N-oxide have been recorded and analyzed in the range 400-4000 cm(-1). The stabilities, optimized molecular geometries, APT charges and vibrational characteristics for the two possible conformers of nicotinamide and its N-oxide have been studied theoretically using restricted Hartree-Fock (RHF) and density functional theory (DFT) methods. The E (trans) conformers of nicotinamide and its N-oxide are found to be more stable and less polar than their respective Z (cis) conformers. Due to addition of an O atom at the N(1) site in the NA molecule the magnitudes of atomic charges on all the H atomic sites are found to increase. For all the studied molecules, magnitude of the wagging mode of the NH(2) group is found to be higher than its torsion mode, which is in the reverse order as compared to that for the aniline molecule. Most of the vibrational frequencies have nearly the same magnitude for the two conformers of nicotinamide and its N-oxide, however, significant changes are noticed in their IR intensities, Raman activities and depolarization ratios of the Raman bands. The frequency of the ring breathing mode for the NA molecule is found to decrease by 100 cm(-1) in going to the NANO molecule for both the conformers. The IR intensity for the scissoring mode of the CON(H(2)) group is found to decrease significantly for the NA-II conformer as compared to that for the NA-I conformer.

DFT study of molecular geometries and vibrational characteristics of uracil and its thio-derivatives and their radical cations

DFT calculations at the B3LYP/6-311++G** level have been carried out to study the vibrational characteristics of the neutral molecules, anionic and cationic radicals of uracil, 2-thiouracil and 4-thiouracil. In the U molecule, C=C bond loses its double bond character and magnitude of the C=C stretching frequency decreases significantly as a result of radicalization. Frequency for the in-plane deformation mode of C=O increases when a sulfur atom is substituted for the oxygen atom at the site C(2) in the uracil molecule but decreases when a sulfur atom is substituted for the oxygen atom at the site C(4). The magnitude of both the N-H stretching frequencies decreases in all the radical cations as compared to their neutral molecules. Radicalization leads to significant changes in the magnitudes and intensities corresponding to some of the normal modes for all the three cases. Removal of an electron leads to decrease in the electronic charge mainly from the sulfur atom in the case of 2-TU and 4-TU, whereas it is distributed over the sites N(1), C(5), O(8) and O(10) in case of the U molecule.

Structural and vibrational studies of molecular conductors using quantum mechanical methods: 1,3-Dithiole-2-thione, 1,3-dithiole-2-one, 1,3-dioxole-2-one and 1,3-dioxole-2-thione

Computations were carried out by employing the RHF and density functional theory (DFT) methods to investigate the geometries, atomic charges, harmonic vibrational frequencies for the 1,3-dithiole-2-thione (DTT), 1,3-dithiole-2-one (DTO), 1,3-dioxole-2-thione (DOT) and 1,3-dioxole-2-one (DOO) molecules and their radical cations. The geometrical parameters and atomic charges on various atomic sites of the DTT and DOT molecules and their radical cations suggest extended conjugation in these systems. Contrary to this, for the DOO(+) and DTO(+) ions there is no evidence in favour of such conjugation, however, the neutral molecules exhibit some conjugation. Harmonic forced field and vibrational mode calculations provided convincing theoretical evidence for the reassignment of some fundamental vibrational modes for all the four molecules. In going from the neutral species to the charged ions for all the four cases the CC stretching frequency is found to decrease drastically. The CS stretching frequency reduces drastically for the DTT and DOT molecules as compared to their radical cations whereas the CO stretching frequency is found to increase in going from the neutral molecule to its radical cation for the DOO and DTO molecules. The ring stretching mode with a(1) symmetry and CC and CO/S stretching modes in these molecules appear to help in conversion of neutral molecule into respective radical cation and neighbouring radical cation into respective neutral molecule. Thus, there appears the feasibility of stretching vibrational mode coupling with electron transfer.

Repaglinide induced acute hepototoxicity

Repaglinide is considered a safe drug; adverse events are mild to moderate which includes hypoglycemia, headache, nausea, vomiting, diarrhea and dyspepsia as similar to sulphonylureas. This case report describes a rare side effect of repaglinide. In rare cases, elevated liver enzymes have been noted. We report a case of acute hepatotoxicity in a 78-year-old woman who developed acute hepatotoxicity while taking repaglinide.

Study on the response of diploid, tetraploid and hexaploid species of wheat to the elevated CO2

Study was done to compare the response of Triticum aestivum (hexaploid), Triticum durum (tetraploid) and Triticum monococcum (diploid) wheat species to the elevated CO2 using Free Air CO2 Enrichment (FACE) facility. It was demonstrated that the modern cultivar of wheat Triticum aestivum (hexaploid) was largely sink limited. It appeared to have less photosynthesis per unit leaf area than Triticum monococcum (diploid wheat). While leaf size, grain weight and amylase activity increased with the ploidy level from diploid to hexaploid wheat forms, the photosynthetic rate was reduced significantly. These wheat species responded differentially to the elevated CO2. The larger leaf area and greater seed weight and presence of 38 KDa protein band caused by elevated CO2 had additive effect in improving the productivity of hexaploid wheat by changing the source sink ratio. Whereas, such a source sink balance was not induced by elevated CO2 in diploid wheat. The increasing CO2 may present opportunities to breeders and possibly allow them to select for cultivars responsive to the elevated CO2 with better sink potential.

Ab initio determination of molecular geometries and vibrational frequencies of CX3 COOH (X=H, F, Cl, Br)

Using Gaussian 03 Revision C.02 version of the quantum chemical program ab initio and DFT computations have been carried out at the rhf/6-31+g*, b3lyp/6-31+g*, b3lyp/6-31++g** and b3lyp/6-311++g** levels to compute optimized geometries, harmonic vibrational frequencies along with intensities in IR and Raman spectra and atomic charges for the acetic (ethanoic) acid and its 1,1,1-tri-halo (fluoro, chloro and bromo) derivatives. The optimized molecular structures for all the four molecules are found to possess Cs point group symmetry. The symmetric stretching mode is found to have lowest magnitude of the three CX3 stretching modes for all the four molecules, whereas the symmetric deformation mode is found to have the lowest magnitude for EA and TFEA and the highest magnitude for TCEA and TBEA. The parallel rocking mode of the CX3 group is found to have lower magnitude than the perpendicular rocking mode for EA and TFEA where reverse is found for TCEA and TBEA. The modes of the COOH group are substituent sensitive except the OH stretching mode. Moreover, the maximum effect is found for the TFEA molecule. The CF3 group is found to have the characteristic frequencies as 235-505, 787, 1150-1190 and 1400 cm(-1) which are due to the modes delta s(CF3), nu s(CF3), nu as(CF3) and nu(C-CF3), respectively.

Comparative evaluation of fungal, tubercular, and pyogenic brain abscesses with conventional and diffusion MR imaging and proton MR spectroscopy

BACKGROUND AND PURPOSE

It is difficult to differentiate the cause of brain abscesses with the use of CT and MR imaging. We did a comparative evaluation of pyogenic, tubercular, and fungal brain abscesses by using conventional, diffusion-weighted imaging (DWI), and proton MR spectroscopy (PMRS) with an aim to define the unique features that may differentiate among the pyogenic, tubercular, and fungal brain abscesses.

MATERIALS AND METHODS

We performed a retrospective analysis on 110 patients with surgically proved brain abscesses. Imaging studies included T2, T1, postcontrast T1, DWI, and PMRS. Apparent diffusion coefficient (ADC) of the wall and cavity of the abscesses were quantified. The morphologic, physiologic, and metabolite features of pyogenic (n=91), tubercular (n=11), and fungal (n=8) abscesses were compared.

RESULTS

The pyogenic abscesses had smooth (55/91) and lobulated (36/91) walls, whereas the tubercular abscesses had smooth (4/11), lobulated (6/11), or crenated walls (1/11) with no intracavitary projections. The fungal abscesses showed irregular walls (lobulated 4/8, crenated 4/8) with intracavitary projections (8/8). The wall as well as the cavity showed low ADC in the pyogenic and tubercular abscesses. In the fungal abscesses, the wall and projections showed low ADC (8/8); however, the cavity itself showed high ADC (8/8). PMRS showed cytosolic amino acids (89/91), acetate (25/91), and succinate (18/91) in the pyogenic abscesses, whereas lipid/lactate (11/11) was seen in the tubercular abscesses. The fungal abscesses showed lipid (4/8), lactate (7/8), amino acids (4/8), and multiple peaks between 3.6 and 3.8 ppm assigned to trehalose (5/8).

CONCLUSION

Based on the morphologic, ADC, and metabolite information, it may be possible to differentiate among the pyogenic, tubercular, and fungal brain abscesses.

Patterns of organophosphorous poisoning attending a teaching hospital

The objective of this was to study the pattern of patients of organophosphorous (OP) poisoning attending Kathmandu Medical College Teaching Hospital (KMCTH). This is a retrospective study of OP poisoning from hospital records were analyzed meticulously and data extracted. Data collected were: patient's demographics, motive for poisoning, type of OP poison, arrival time, time since ingestion, patient's vitals, predisposing factors, serum cholinesterase levels, treatment given, duration of hospital stay and mortality. A total of 47 patients of OP poisoning attended KMCTH from Aug 2003 to July 2005. 22(46.8%) cases were male and 25(53.2%) were female. The maximum number of patients were between the age of 20-40 (33-70.2%). Married patients outnumbered the unmarried (35/74.5% vs 12/25.5%). The most common motive for poisoning was suicidal, 41 cases (87.2%). Metacid (methyl-parathion) was the most commonly used OP compounds in 32 (68%) patients. Interpersonal marital relationship seemed to be the commonest predisposing factor, 23 cases (48.9%). The commonest time of presentation was between 6 pm-12 midnight. 7(57.4%) cases presented within 2 hours of ingestion of the poison. Serum cholinesterase level measured after full atropinisation was >50% of normal level in 17 cases (36.2%). 10 cases (21.3%) required respiratory support. Intermediate syndrome (IMS) was observed in 3 cases. Overall mortality occurred in 3 cases (6.4%). This study highlights the problem of OP poisoning in our region. Establishment of strict policies against the sale and availability of insecticides and pesticides which are freely available in the market is an effective way to control OP poisoning.

Quenching of CdSe quantum dot emission, a new approach for biosensing

The emission of CdSe quantum dots linked to the 5'-end of a DNA sequence is efficiently quenched by hybridisation with a complementary DNA strand with a gold nanoparticle attached at the 3'-end; contact of the quantum dot and gold nanoparticle occurs.

Hyperammonemia: an unusual presenting feature of multiple myeloma

A 76 year old lady presented with altered sensorium and was found to have hyperammonemia on evaluation. She had no evidence of liver disease. For her symptomatology of backache, evaluation by bone marrow study showed evidence of multiple myeloma. She was given chemotherapy for multiple myeloma, which resulted in improvement in her sensorium, along with this there was also a rapid decline in serum ammonia levels. Hyperviscosity and hypercalcemia are common causes of altered sensorium in a patient with myeloma but in this case hyperammonemia was the likely cause.

HIV/AIDS and STI related knowledge, attitude and practice among high school students in Kathmandu valley

OBJECTIVE

To assess the knowledge, attitude and practice of high school students regarding HIV/ AIDS and STI and to determine if a school education programme would bring about statistically significant positive change in the knowledge, attitude and practice regarding HIV/AIDS and STI.

METHODS

The study was conducted among 1012 students of various schools in Kathmandu Valley (Kathmandu, Bhaktapur and Lalitpur). The tool for assessment was confidentially administered closed questionnaire both before and after the education programme of 45 minutes single class, standardized education package.

RESULTS

Knowledge on some aspect of the disease was quite low in the study group. 45.8% had prior knowledge of HIV, 65.2% knew that HIV/AIDS could be transmitted by sharing same needle, 46.2% knew that vaccine is not yet available for HIV/AIDS. Knowledge about STI was also quite low, 41.5% knew that pus in the urine is a symptom of STI and 41.7% knew that STI is curable. 4.2% of the study group had previous sexual intercourse, 64.2% had sexual intercourse with friend and 35.17% had sexual intercourse with commercial sex workers. 1.8% would commit suicide if they contracted HIV/AIDS. According to sex wise distribution of the sample, female's knowledge about HIV was low 43.2% as compared to male 48%, male's knowledge about transmission of HIV/AIDS from pregnant mother to child was low; 89.7% as compared to female's knowledge 94.2%. Female's knowledge about commercial sex worker as high risk group was low (87.8%) as compared to male's knowledge 90.6%.

Marfan's syndrome with aortic valve endocarditis

Marfans syndrome is an Autosomal dominant disorder of the connective tissues resulting in abnormalities of the musculoskeletal system, cardiovascular system and eyes. It has a prevalence of 1 in 100,000 population1 and occurs in all ethnic groups. It may be familial or due to new mutation (30%), in the fibrillin gene on arm of chromosome 15. It is estimated that one person in every 3000-5000 has Marfans syndrome may have cardiovascular abnormalities and may be complicated by infective endocartditis. About 90% of Marfan patients will develop cardiac complications2. The patient under discussion has musculoskeletal (Tall stature, reduced upper-lower segment ratio, arm-span to height ratio > 1.05, high arched palate) and Cardiovascular features (Severe aortic regurgitation complicated with infective endocarditis).

Production of secretory IgA antibodies in plants

Functional antibodies produced in tobacco plants were first reported over a decade ago (1989). The basic protocol used to generate these 'plantibodies' involved the independent cloning of H and L chain antibody genes in Agrobacterium tumefaciens vectors, the transformation of plant tissue in vitro with the recombinant bacterium, the reconstitution of whole plants expressing individual chains, and their sexual cross. In a 'Mendelian' fashion, a fully assembled and functional antibody was recovered from plant tissue in some double-transgenic plants. In mammalian cells, the antibody H and L chains are produced as precursor proteins that are translocated into the endoplasmic reticulum (ER), under the guidance of signal sequences. Within the ER, the signal peptides are proteolytically cleaved, and several stress proteins act as chaperonins to bind the unassembled antibody chains, and direct subsequent folding and tetramer formation. A similar process occurs in plant cells, and expression can be directed via signal sequences (even of foreign origin) into the aqueous environment of the apoplasm, or to be accumulated in other specific plant tissues, including tubers, fruit, or seed. Plants can facilely assemble secretory IgA, which is comprised of four chains, H and L chains, J chain and secretory component. Plant 'bioreactors' are expected to yield over 10 kg of therapeutic antibody/acre in tobacco, maize, soybean, and alfalfa [(Ann. NY Acad. Sci.)721(1994)235; (Biotechnol. Bioeng.)20(1999)135]. Compared with conventional steel tank bioreactors using mammalian cells, or microorganisms, the costs of GMP plantibodies are expected to perhaps one tenth. The differences in glycosylation patterns of plant and mammalian cell produced antibodies apparently have no effect on antigen-binding or specificity, but there is some concern about potential immunogenicity in humans. N-linked glycans of plants differ from human by having fucose-linked alpha 1,3 and the sugar xylose. No adverse effects or human anti-mouse antibodies (HAMA) have been observed in >40 patients receiving topical oral application of a plant produced secretory IgA specific to Streptococcus mutans, for the control of caries [(Nat. Med.)4(1998)601]. The progressive improvement of expression vectors for plantibodies, and purification strategies, as well as the increase in transformable crop species, is expected to lead to almost limitless availability of inexpensive (even edible forms of) recombinant immunoglobulins free of human pathogens for human and animal therapy, and for novel industrial applications (e.g. catalytic antibodies).

Production of antibodies in transgenic plants

Plants offer a cost-effective bioreactor to produce antibodies of diverse types. Recent studies demonstrate that secretory IgA, the predominant antibody isotype of the mucosal immune system, can be made in large quantities in plants. CaroRx, the lead SIgA antibody being developed by Planet Biotechnology Inc., has demonstrated activity in pilot phase II trials versus S. mutans, the major pathogen contributing to development of dental caries. Numerous other SIgA plantibodies are in preclinical development.

Central motor conduction time in malnourished children

The functional status of the descending motor pathways was assessed in malnourished children using transcranial electromagnetic stimulation of the cortex. Twenty children with different severities of malnutrition and 20 control subjects were studied electrophysiologically. The circular coil of a Dentac MAG 2 magnetic stimulator was applied tangentially over the vertex to stimulate the cortex. The muscle evoked potential in the children's arms was recorded from the abductor pollicis brevis muscle and in their legs from the extensor digitorum brevis muscle on both sides of the body using surface electrodes. The muscle evoked potential of the abductor pollicis brevis and extensor digitorum brevis muscles was further obtained using root stimulation by applying the coil at the cervical and lumbar spine, respectively. The indices of cortical threshold, cortical latency, and central motor conduction time (ms) were evaluated in both arm and leg muscles on both sides. The results showed an increased cortical threshold (mean (SD) 1232.5 (134.06) in the study group v 1147.5 (99.31) in the control group) for the abductor pollicis brevis muscle and for the extensor digitorum brevis muscle (1325.00 (115.70) in the study group v 1190.0 (125.24) in the control group). Similarly, significant prolongation of the central motor conduction time (ms) (study group 6.67 (0.91) v control group 5.71 (0.74)) in the abductor pollicis brevis muscle was seen in malnourished children.