Synthesis, characterization and anticoagulant activity of chitosan derivatives

Chitosan derivatives are reported as anticoagulants in the literature. This work was undertaken to develop novel chitosan derivatives as anticoagulants. The sulfonated derivatives of chitosan were formed by the reaction of chitosan derivatives with chlorosulfonic acid in N,N-dimethylformamide. The structures of these derivatives were established by FTIR and ¹H NMR spectra. The prepared derivatives were evaluated for their in vivo anticoagulant effects by the tail bleeding method in Wistar rats utilizing nicoumalone as a standard drug. The results revealed that the sulfonation of the chitosan increases its anticoagulant activity. The developed compounds exhibited faster onset of action and potency than nicoumalone after one hour of the drug administration. The sulphated N-alkyl derivatives of chitosan were more potent anticoagulants than sulfated quaternary derivatives/sulfated chitosan. It is also suggested to develop analogs of Ethyl chitosan sulfate (4b) and Benzyl chitosan sulfate (4c), which may provide some more fruitful anticoagulants having faster onset of action as well as longer duration of action and possessing a balanced hydrophilic/lipophilic character.

Youngest documented rheumatic mitral stenosis with regurgitation in a 28-month-old girl

BACKGROUND

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are the leading causes of acquired diseases in children and young adults in developing countries carrying considerable morbidity and mortality. Rheumatic fever (RF) commonly affects children between 5-15 years old and is rarely seen in < 5 years old. Mitral stenosis (MS) is the most common sequela, as it bears maximum onslaught. In India, few patients follow an unusually rapid course in developing severe MS because of its fulminant nature following attack of ARF.

CASE REPORT

Our patient was a 28-month-old girl who had developed severe MS, mitral regurgitation (MR), and pulmonary hypertension (PH) as the sequelae of ARF which she had suffered at the age of 18 months old.

CONCLUSION

To the best of our knowledge, this is the youngest reported case of rheumatic MS following ARF after extensive search in the literature. This case highlights the fact that very young population is not immune to ARF contrary to prior belief and therefore, more stringent preventive measures need to be implemented for it and possibility of ARF should be kept in mind while evaluating carditis in a child.

Silver Quantum Dot Decorated 2D-SnO2 Nanoflakes for Photocatalytic Degradation of the Water Pollutant Rhodamine B

Decoration of 2D semiconductor structures with heterogeneous metal quantum dots has attracted considerable attention due to advanced optical, electrical, and catalytic properties that result from the large surface-to-volume ratio associated with these structures. Herein, we report on silver quantum dot decorated 2D SnO₂ nanoflakes for the photocatalytic abatement of water effluents, the synthesis of which was achieved through a straightforward and mild hydrothermal procedure. The photocatalysts were systematically investigated using UV–Vis, XRD, electron microscopy (SEM, HR-TEM), EDX, XPS and FTIR. The photocatalytic activity of the nanostructures was evaluated for the abatement of water pollutant rhodamine B (RhB), under light irradiation. The mild hydrothermal synthesis (100 °C) proved highly efficient for the production of large scale Ag quantum dot (QD)/SnO₂ nanoflakes for a novel photocatalytic application. The decoration of SnO₂ with Ag QDs significantly enhances the synergetic charge transfer, which diminishes the photo-induced electron-hole reunion. Moreover, the plasmonic effect from Ag QDs and 2D-SnO₂ structures acts as an electron tank to collect the photo-induced electrons, generating a Schottky barrier between the SnO₂ structures and quantum dots. Overall, this resulted in a facile and efficient degradation of RhB, with a rate double that of pristine SnO₂.

Spectrum of Biopsy Proven Extraocular Muscle Tumours of Non-Thyroid Origin

OBJECTIVE

To describe different types of primary extraocular muscle (EOM) tumours based on the results of imaging studies, peroperative clinical picture and their histopathological diagnosis.

STUDY DESIGN

Case series.

PLACE AND DURATION OF STUDY

Al-Shifa Trust Eye Hospital, Rawalpindi, from July 2001 to January 2017.

METHODOLOGY

A retrospective analysis of 640 diagnosed orbital tumours was carried out using non-randomised sampling technique, and the prevalence of primary EOM tumours was determined. Based on the results of imaging studies, the clinical picture observed during surgery (orbitotomy) and the histopathological diagnosis, primary EOM tumours were divided into different types, accordingly.

RESULTS

Nineteen (n=19) primary EOM tumours (frequency of 2.96%) had 12 types of histopathological diagnoses, and were categorised into inflammatory tumours (n=8, 42%), vascular tumours (n=4, 21%), lymphoproliferative tumours (n=3, 16%), neurogenic tumours (n=2, 10.5%) and myogenic tumours (n=2, 10.5%). The recti were involved more frequently than obliques (n=15, 78.94% and n=4, 21.06%, respectively). All the patients presented with proptosis of varying degree with some degree of globe rotation and had surgical excision/appropriate management. Visual acuity was not affected in any of the patients. Four (n=4, 21.05%) tumours were malignant (NHL, ASPS, myeloid sarcoma and rhabdomyosarcoma) and these patients underwent chemotherapy and/or radiotherapy.

CONCLUSION

Biopsy-proven primary EOM tumours were devisable into five broad categories. Patients with primary EOM tumours presented with proptosis and impaired ocular motiliy. The primary EOM tumours involved both the recti and the obliques and were excised surgically with favourable outcomes in most cases.

Routine monitoring of liver function tests in lung cancer resections - a necessary burden?

BACKGROUND

Increased availability of routine investigations results in significant over-investigation, burdening patients with unnecessary tests as well as increasing cost. We aimed to identify the extent of monitoring of liver function tests in lung resections, and to ascertain whether any impact on clinical decision-making occurred.

METHODS

Cases were identified using theatre records coded as "lobectomy/bilobectomy" in the three-month period 20 June 2017 to 20 September 2017. Electronic records were used to collect patient data.

RESULTS

A total of 91 cases were included; 77 (85%) patients had 1 set of pre-operative LFTs, 12 (13%) patients had 2 sets, and 2 (2%) patients had 0 sets; 69 (76%) had normal LFTs pre-operatively; 298 sets of LFTs were measured post-operatively, with a median of 3 sets per patient; 61 (67%) patients had either normal or static LFTs post-operatively, 13 (14%) had isolated rise in GGT, 16 (17%) had derangement of ALT and AST, and 1 patient (1%) had deranged ALP. Altered clinical decision-making due to LFTs derangement was recorded in two cases (2%).

CONCLUSION

Clinicians have an obligation to justify expense, and practise in a cost-effective manner. Our data suggest that the routine perioperative monitoring of LFTs in thoracic surgery does not give any clear benefit to patient care.

A Mesopore-Dependent Catalytic Cracking of n-Hexane Over Mesoporous Nanostructured ZSM-5

Herein, pore size, crystalinity, and Si/Al ratio of mesoporous ZSM-5 (MFI) nanocrystals was controlled by synthesis parameters, such as surfactant concentration ([3-(trimethoxysilyl)propyl] hexa-decyl dimethyl ammonium chloride), sodium hydroxide concentrations, synthesis temperature and time. The morphology, surface structure and composition of the MFI particles was systematically investigated. More notably, the mesopore-dependent catalytic activity of ZSM-5 was evaluated by studying the cracking of n-hexane. The findings suggest the porosity has pronounced impact on the catalytic activity, selectivity and stability of ZSM-5 nanocrystals. Critical surface attributes such as nature of acid sites (Brønsted and Lewis), concentration, and strength are obtained by the infrared study of adsorbed probe molecules (pyridine) and the temperature programmed desorption. In spite of being weaker in Si/Al ratio or acidic strength, mesoporous catalysts showed more stable and efficient cracking of n-hexane suggesting that acidity seems not the predominant factor operative in the activity, selectivity and stability.

Adsorptive removal of phenolic compounds from aqueous solutions using pine cone biomass: kinetics and equilibrium studies

In this study, a novel inexpensive biosorbent of pine cone powder was used for the treatment of wastewater contaminated with phenol and chlorophenols (CPhs). The biosorbent was thoroughly characterized by using CHN and BET measurements, as well as FTIR, SEM, and XRD analyses. Kinetic and equilibrium biosorption experiments showed that the uptake was more than 80% within the first 30 min of contact time at pH 5.0. The biosorption of 4-CPh onto pine cone powder was higher than those of phenol and 2-CPh. The kinetic data were consistent with the pseudo-first-order kinetic model, and the Langmuir isotherm model best represented the equilibrium data. The maximum biosorption capacities of phenol, 2-CPh, and 4-CPh were 164.51, 189.44, and 220.12 mg/g, respectively, at 30 ± 1 °C. Therefore, the pine cone powder is an effective low-cost adsorbent for the removal of phenol and CPhs from the contaminated water.

M2 polarization of macrophages by Oncostatin M in hypoxic tumor microenvironment is mediated by mTORC2 and promotes tumor growth and metastasis

Oncostatin M (OSM), an inflammatory cytokine belonging to the interleukin-6 (IL-6) superfamily, plays a vital role in multitude of physiological and pathological processes. Its role in breast tumor progression and metastasis to distant organs is well documented. Recent reports implicate OSM in macrophage M2 polarization, a key pro-tumoral phenomenon. M2 polarization of macrophages is believed to promote tumor progression by potentiating metastasis and angiogenesis. In the current study, we delineated the mechanism underlying OSM induced macrophage M2 polarization. The findings revealed that OSM skews macrophages towards an M2 polarized phenotype via mTOR signaling complex 2 (mTORC2). mTORC2 relays signals through two effector kinases i.e. PKC-α and Akt. Our results indicated that mTORC2 mediated M2 polarization of macrophages is not dependent on PKC-α and is primarily affected via Akt, particularly Akt1. In vivo studies conducted on 4T1/BALB/c mouse orthotropic model of breast cancer further corroborated these observations wherein i.v. reintroduction of mTORC2 abrogated monocytes into orthotropic mouse model resulted in diminished acquisition of M2 specific attributes by tumor associated macrophages. Metastasis to distant organs like lung, liver and bone was reduced as evident by decrease in formation of focal metastatic lesions in mTORC2 abrogated monocytes mice. Our study pinpoints key role of mTORC2-Akt1 axis in OSM induced macrophage polarization and suggests for possible usage of Oncostatin-M blockade and/or selective mTORC2 inhibition as a potential anti-cancer strategy particularly with reference to metastasis of breast cancer to distant organs such as lung, liver and bone.

Biosorption of 2,4,6-trichlorophenol from Aqueous Medium Using Agro-waste: Pine (Pinus densiflora Sieb) Bark Powder

Most industrial waste discharges are often contaminated with phenolic compounds, which constitute a major source of water pollution owing to their toxicity and low biodegradability. Development of cost-effective treatment of such industrial wastewater is therefore of paramount importance. Towards this end, we explore the efficacy of Pine bark powder (PBP), which is an agricultural solid waste material, as a low-cost biosorbent without any pre-treatment, for the adsorptive removal of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous media. The PBP was thoroughly characterized and the effect of important adsorption parameters were examined in the present investigation. The batch equilibrium data were analyzed using well-known isotherm models. Freundlich isotherm model provided the best description of the equilibrium biosorption behavior. At 25 ± 1 °C, the maximum biosorption capacity (qmax) was 289.09 mg/g, which is higher than most biosorbents reported in the literature while the removal as high as 97% was obtained. Moreover, the biosorption process was fast, attaining equilibrium in less than 120 min of contact. The Elovich model accurately described the kinetics data. In view of high biosorption capacity and.

A Study to Assess the Efficacy of Different Doses of Propofol for Tracheal Intubation: A Randomized Clinical Trial

BACKGROUND

Tracheal intubation is usually facilitated by using a muscle relaxant to supplement drugs given for the induction of general anesthesia. Nondepolarizing muscle relaxants are also associated with the few disadvantages. Endotracheal intubation under volatile anesthetics without the use of muscle relaxants is possible, but it has disadvantages. Time available for intubation is much less when compared to the use of muscle relaxants. Considering the disadvantages of muscle relaxants and volatile agents in mind, there is a need for endotracheal intubation without muscle relaxants.

OBJECTIVE

The objective of the study is to assess the efficacy of different doses of propofol for tracheal intubation - a randomized clinical trial.

MATERIALS AND METHODS

A randomized study was conducted on 80 patients, comprising of 40 patients each. Patients of either sex were randomly allocated into Group P1 and Group P2 by computer-generated random numbers where Group P1 received 2 mg/kg propofol +3 μg/kg fentanyl and Group P2 received 4 mg/kg propofol +3 μg/kg fentanyl. SpO₂, heart rate, blood pressure (BP)- systolic BP, diastolic BP, and mean arterial pressure were recorded at 1 and 3 min after administration of study drugs were recorded. Intubating conditions were assessed modified Helbo-Hansen scoring system.

RESULTS

The success rate of endotracheal intubation was 62.5% and 95% in propofol 2 mg/kg + fentanyl 3 μg/kg and propofol 4 mg/kg + Fentanyl 3 μg/kg, respectively. The total incidence of hypotension was 40% and 83% in propofol 2 mg/kg + Fentanyl 3 μg/kg and propofol 4 mg/kg + Fentanyl 3 μg/kg, respectively. The incidence of hypersensitivity was noted only in propofol 4 mg/kg + Fentanyl 3 μg/kg group and was 2.5%.

CONCLUSION

We conclude that endotracheal intubation is possible in premedicated adult American Society of Anesthesiologists by Grade I patients with receiving 3 μg/kg Fentanyl + 2 mg/kg or 4 mg/kg propofol for induction without muscle relaxants, and the intubating conditions are acceptable. We found that propofol 4 mg/kg + Fentanyl 3 μg/kg is the optimal dose required for intubation without the use of muscle relaxants.

Pyridinium-clubbed dicationic ionic liquid electrolytes for efficient next-generation photo harvesting

A new series of pyridinium based dicationic ionic liquids was designed and synthesized. The synthesized ionic liquids have excellent thermal stability and good ionic conductivity. They can be used as electrolytes in photovoltaic devices.