Recent progress in MoS2 nanostructures for biomedical applications: Experimental and computational approach

In the category of 2D materials, MoS2 a transition metal dichalcogenide, is a novel and intriguing class of materials with interesting physicochemical properties, explored in applications ranging from cutting-edge optoelectronic to the frontiers of biomedical and biotechnology. MoS2 nanostructures an alternative to heavy toxic metals exhibit biocompatibility, low toxicity and high stability, and high binding affinity to biomolecules. MoS2 nanostructures provide a lot of opportunities for the advancement of novel biosensing, nanodrug delivery system, electrochemical detection, bioimaging, and photothermal therapy. Much efforts have been made in recent years to improve their physiochemical properties by developing a better synthesis approach, surface functionalization, and biocompatibility for their safe use in the advancement of biomedical applications. The understanding of parameters involved during the development of nanostructures for their safe utilization in biomedical applications has been discussed. Computational studies are included in this article to understand better the properties of MoS2 and the mechanism involved in their interaction with biomolecules. As a result, we anticipate that this combined experimental and computational studies of MoS2 will inspire the development of nanostructures with smart drug delivery systems, and add value to the understanding of two-dimensional smart nano-carriers.

Photonic nanoparticles: emerging theranostics in cancer treatment

This review explores the potential of photonic nanoparticles for cancer theranostics. Photonic nanoparticles offer unique properties and photonics capabilities that make them promising materials for cancer treatment, particularly in the presence of near-infrared light. However, the size of the particles is crucial to their absorption of near-infrared light and therapeutic potential. The limitations and challenges associated with the clinical use of photonic nanoparticles, such as toxicity, immune system clearance, and targeted delivery to the tumor are also discussed. Researchers are investigating strategies such as surface modification, biodegradable nanoparticles, and targeting strategies to improve biocompatibility and accumulation in the tumor. Ongoing research suggests that photonic nanoparticles have potential for cancer theranostics, further investigation and development are necessary for clinical use.

Adrenal Myelolipoma Mimics Ectopic Adrenal or Renal Tissue: An Incidental Finding During Cadaveric Dissection

Context

On naked eye examination adrenal myelolipoma (AML) tissue appears to be an ectopic adrenal or renal tissue, based on the similarity to their external texture. This necessitates a histo-pathological study for confirming the origin of the tissue.

Objective

To establish the origin and histological features of the incidental AML tissue found during cadaveric dissection and review the literature for similar findings with clinical picture and treatment description.

Subjects and Methods

Unilateral adrenal gland obtained from cadaveric dissection was subjected to histological study by H & E staining of the slides prepared. The literature review was done from articles published in PubMed indexed journals.

Case report

A case of an incidental finding of AML during cadaveric dissection is presented which on naked eye examination was appearing to be an ectopic adrenal or renal tissue, based on the similarity to their external texture. On histological examination, a thin rim of adrenocortical tissue, surrounding the mature adipose tissue, and attenuated by islets of myeloid, erythroid and megakaryocytic cell lines in varying proportions, resembling the mature bone marrow morphology, was observed. The literature review on PubMed explains similar incidental post-mortem autopsy findings due to the asymptomatic nature of the tumor. The incidence of AML varied between 0.08% and 0.2% in the last decade of the 20^th century, which increased up to 10 - 15% of incidental adrenal masses due to the widespread use of non-invasive imaging modalities leading to an increase in the diagnosis of the pathology.

Conclusions

Before considering the ectopic incidence of tissue during cadaveric dissection, a histo-pathological examination is mandatory for confirmation. Adreno-myelolipoma is an asymptomatic post-mortem finding in 10-15% of cases of adrenal tissue which mimics ectopic adrenal gland or renal tissue due to its external texture.

Dose-dense Paclitaxel and Carboplatin as Neoadjuvant Chemotherapy for Stage IIB/IIIA Non-small Cell Lung Cancer - A Phase II trial

AIMS

The approach to potentially resectable non-small cell lung cancer (NSCLC) remains controversial. There is a benefit of neoadjuvant chemotherapy (NACT), but the ideal regimen is unknown. We evaluated the efficacy and safety of dose-dense NACT in potentially resectable NSCLC in this phase II trial.

MATERIALS AND METHODS

Paclitaxel at 80 mg/m² on days 1, 8 and 15 with AUC-6 carboplatin on day 1, 3 weekly for four cycles was evaluated as NACT. Patients with Eastern Cooperative Oncology Group performance status 0-2, stage IIB and IIIA (with only non-bulky N2 nodes) were included. The primary end point was the objective response rate. Secondary end points included toxicity, progression-free survival, recurrence-free survival, complete resection rate and overall survival. The relative dose intensity (RDI) was calculated to define tolerability (CTRI/2016/05/006916).

RESULTS

In total, 37 patients were enrolled (median age 55 years). Most (78.8%) were smokers. Most patients had adenocarcinoma (57.6%) and stage IIIA disease (81.0%) according to the seventh American Joint Committee on Cancer staging system. Seventy-eight per cent of patients completed four cycles. The objective response rate was 75.6% with a complete response in 10.8%. The mean RDI of paclitaxel was 88.61%, with 68.0% of patients able to maintain an RDI ≥85.0%. In total, 187 toxicity events were recorded (120 grade 1, 64 grade 2 and three grade 3 events). Common toxicities were peripheral neuropathy (20.3%), myalgia (19.8%), nausea (15.7%) and neutropenia (10.2%). There were no treatment-related deaths. Seventeen patients underwent surgery (lobectomy 82.4%). After a median follow-up of 47 months (95% confidence interval 27-50.7 months), the median progression-free survival was 9.6 months (7.4-17.4) and overall survival was 29.2 months (16.0-37.2).

CONCLUSION

Dose-dense paclitaxel-carboplatin is feasible, safe and efficacious and should be evaluated further in potentially resectable NSCLC.

Effect of dopant concentration and the role of ZnS shell on optical properties of Sm3+ doped CdS quantum dots

The role of samarium (Sm) dopant on the structural, morphological, and optical properties of CdS QDs and CdS/ZnS core/shell QDs was methodically reported. The synthesis of Sm-doped CdS QDs and CdS/ZnS QDs was carried out via a facile wet chemical method. The structure, chemical composition, and optical properties of the synthesized QDs were investigated by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), and photoluminescence (PL) spectroscopy. XRD analysis showed that the synthesized CdS QDs exhibited zinc blende structure which was not affected by doping Sm3+ ions. The particle size of the CdS:Sm and CdS:Sm (2%)/ZnS QDs was estimated to be ∼4 nm and ∼7 nm, respectively. Transmission electron microscopy (TEM) images revealed that the incorporation of Sm dopant did not significantly affect the size and morphology of CdS QDs, while the formation of the ZnS shell increased the particle size. XPS and XRD results confirmed the successful incorporation of Sm3+ ions into the CdS QDs. The effect of dopant concentration on the structural and luminescent properties was studied. The emission and excitation spectra of Sm3+-doped CdS QDs and CdS/ZnS QDs consisted of the characteristic lines corresponding to the intra-configurational f-f transitions. The energy transfer (ET) mechanism from the host to Sm3+ ions and the ET process through cross-relaxation between Sm3+ ions have been elucidated. The effect of the ZnS shell on the optical stability of the Sm3+-doped CdS QDs was studied in detail and the results showed that the CdS:Sm (2%)/ZnS QDs retained their good emission characteristics after 376 days of fabrication. The luminescent properties of Sm-doped QDs ranging from violet to red and PL lifetime extending to milliseconds demonstrated that these QDs are the potential materials for applications in white LEDs, biomarkers, and photocatalysis.

Characteristics and mechanism associated with drug conjugated inorganic nanoparticles

Nanoparticles have several exciting applications nowadays almost in every area. Biomedical field is one of them where nanoparticles show potential for various applications due to their exceptional and exciting properties. The presence of heavy metals in inorganic nanoparticles lead to toxicity in the biological system, therefore, their direct use for drug delivery is restricted. But encapsulating their surface with a non-toxic or biocompatible material makes them a promising material for application in drug delivery system. This review highlights the various characteristics and factors involved in nano-drug delivery system. The understanding of various mechanisms involved during the uptake of nanoparticles by cells, toxicity, surface chemistry and several drug release mechanisms has been discussed. This article also includes various computational studies used to optimise the design and properties of drug delivery system.

Impact of metabolic syndrome on re-stenosis development: role of drug-eluting stents

Metabolic syndrome (MetS) is defined as a cluster of numerous cardiovascular risk factors, which encompasses obesity, dyslipidaemia, insulin resistance and hypertension. Patients with MetS are more prone to developing cardiovascular events than other patients. To date, several approaches such as physical exercise, dietary control and invasive and non-invasive therapeutic interventions for dyslipidaemia, hypertension and insulin resistance have been used to manage MetS. However, there is a progressive elevation in the incidence of fatal and non-fatal cardiovascular events due to the increased prevalence of obesity and diabetes. Percutaneous coronary intervention has emerged over the last few years as an effective revascularisation strategy for those with coronary artery disease, in parallel with the development of effective anti-platelet medications and newer drug-eluting stents. In recent years, considerable research efforts have been undertaken to elucidate the pathophysiology of re-stenosis and develop strategies to prevent re-stenosis following percutaneous transluminal coronary angioplasty and stent implantation. Although the rate of stent re-stenosis and target-lesion revascularisation has been reduced, there is little information in the literature on the outcome of MetS in the pathophysiology of re-stenosis. In this review article, we summarise the recent development and progress on re-stenosis and the role of drug-eluting stents, particularly in MetS.

Telmisartan, a dual ARB/partial PPAR-γ agonist, protects myocardium from ischaemic reperfusion injury in experimental diabetes

AIM

Apart from its angiotensin receptor blocker (ARB) activity, telmisartan is also a partial agonist of peroxisome proliferator-activated receptor gamma (PPAR-γ). Therefore, we assessed whether telmisartan treatment attenuates myocardial ischaemia/reperfusion (I/R) injury in diabetic rats through PPAR-γ pathway.

METHODS

Diabetic rats were randomized to receive vehicle (sham and I/R), telmisartan (10 mg/kg/day, orally), PPAR-γ antagonist GW9662 (1 mg/kg/day, intraperitoneally) or both for 14 days. On 15th day, excluding sham group, left anterior descending coronary artery occlusion was performed for 45 min followed by 1 h of reperfusion. Haemodynamic, biochemical, histopathological, ultrastructural, immunohistochemical (Bax and Bcl-2 protein), TUNEL positivity, infarct size and western blot studies were performed.

RESULTS

Telmisartan treatment significantly improved cardiac function by normalizing mean arterial pressure, left ventricular pressure (±LVdP/dt(max) , a marker of myocardial contraction and relaxation), by decreasing left ventricular end-diastolic pressure (a marker of preload, 3.7 ± 0.41 vs. 7.3 ± 0.89, p < 0.001) and percent infarct area (37.52 ± 5.83 vs. 46.27 ± 3.20, p < 0.01) as compared to diabetic I/R group. Interestingly, GW9662 worsens the I/R injury (percent infarct area, 54.38 ± 6.48 vs. 46.27 ± 3.20, p < 0.01), whereas telmisartan with GW9662 (percent infarct area, 41.16 ± 8.23 vs. 46.27 ± 3.20, p < 0.05) showed lesser significant results as compared to telmisartan alone. Additionally, telmisartan significantly ameliorates activities of endogenous antioxidants, creatine kinase-MB isoenzyme, lactate dehydrogenase and prevented the increase of tumour necrosis factor-alpha and malondialdehyde in myocardium. Furthermore, telmisartan also decreased Bax expression (4.45 ± 1.24% vs. 10.25 ± 0.96%, p < 0.01), number of TUNEL-positive cells (6.2 ± 0.98% vs. 13.0 ± 1.6, p < 0.01), inflammation, myonecrosis and increased Bcl-2 expression (5.45 ± 0.15% vs. 1.24 ± 0.3%, p < 0.01). On the other hand, GW9662 treatment alone increased the Bax expression, TUNEL positivity and decreased Bcl-2 expression. Telmisartan protective effects were partially attenuated by a co-administration with GW9662. Western blot analysis showed that telmisartan treatment enhanced PPAR-γ expression, whereas GW9662 decreased it in myocardium.

CONCLUSIONS

In addition to the class effect of ARBs, telmisartan has a beneficial effect in I/R injury in diabetic rats in part because of activation of PPAR-γ.

Analysis of elevated temperature-induced inhibition of photosystem II using chlorophyll a fluorescence induction kinetics in wheat leaves (Triticum aestivum)

Wheat is the major crop plant in many parts of the world. Elevated temperature-induced changes in photosynthetic efficiency were studied in wheat (T. aestivum) leaves by measuring Chl a fluorescence induction kinetics. Detached leaves were subjected to elevated temperature stress of 35 °C, 40 °C or 45 °C. Parameters such as Fv/Fm, performance index (PI), and reaction centre to absorbance ratio (RC/ABS) were deduced using radial plots from fluorescence induction curves obtained with a plant efficiency analyser (PEA). To derive precise information on fluorescence induction kinetics, energy pipeline leaf models were plotted using biolyzer hp3 software. At 35 °C, there was no effect on photosynthetic efficiency, including the oxygen-evolving complex, and the donor side of PSII remained active. At 40 °C, activity was reduced by 14%, while at 45 °C, a K intermediate step was observed, indicating irreversible damage to the oxygen-evolving complex. This analysis can be used to rapidly screen for vitality and stress tolerance characteristics of wheat growing in the field under high temperature stress.

Endothelin receptor antagonist BQ-123 ameliorates myocardial ischemic-reperfusion injury in rats: a hemodynamic, biochemical, histopathological and electron microscopic evidence

We investigated the effect of BQ-123, a selective endothelin-A (ET(A)) receptor antagonist in ischemia-reperfusion (IR) induced myocardial infarction (MI) with and without endothelin-1 (ET-1) challenge. MI was produced in rats by occlusion of left anterior descending coronary artery for 40 min and reperfusion for 120 min. ET-1 was administered immediately prior to coronary occlusion whereas vehicle or BQ-123 was administered 20 min after the occlusion. IR control group exhibited marked hemodynamic changes along with significant impairment of left ventricular functions. In addition, oxidative stress was increased, as evidenced by marked reduction in the activities of antioxidants and cardiac injury markers in myocardium. Furthermore, light microscopic and ultrastructural changes revealed myocardial necrosis, edema and inflammation. Prior administration of ET-1 acts synergistically with IR injury and further aggravates the impairment of ventricular functions, increased percent infarct area and decreased antioxidant levels. However, treatment with BQ-123 (1 mg/kg, IV) with or without ET-1 caused significant improvement in cardiac functions, percent infarct area, decreased malonaldehyde level, restored myocardial enzymes activities and maintained the redox status of the myocardium as compared to IR control group. Further, histopathological and ultrastructural studies reconfirmed the protective action of BQ-123. The results of present study suggest that ET-1 acting via ET(A) receptor may exaggerate myocardial damage produced by IR injury and selective blockade of ET(A) receptor by BQ-123 might offer potential cardioprotective action.

Protective effect of Calotropis procera latex extracts on experimentally induced gastric ulcers in rat

AIM OF THE STUDY

Calotropis procera is a wild growing plant with multifarious medicinal properties. The present study was carried out to evaluate the effect of dried latex (DL) of Calotropis procera and its methanol extract (MeDL) against gastric ulcers induced in rats.

MATERIALS AND METHODS

Aqueous suspension of DL (20 and 100mg/kg) and MeDL (10 and 50mg/kg) were given orally to 36h fasted rats and ulcers were induced by ethanol, pyloric ligation and aspirin. Parameters like ulcer score and levels of oxidative stress markers were measured in all the models. The effect on gastric hemorrhage and tissue histology was studied in ethanol model and on acidity, pH and volume of gastric secretion was evaluated in pyloric ligation model. The protective effect of DL and MeDL was compared with that of standard anti-ulcer drug famotidine (20 mg/kg).

RESULTS

DL and MeDL produced 85-95% inhibition of gastric mucosal damage in ethanol model and 70-80% inhibition in aspirin model. The protective effect of these extracts was associated with marked reduction in gastric hemorrhage, maintenance of tissue integrity and normalization of levels of oxidative stress markers like glutathione, thiobarbituric acid reactive substances and superoxide dismutase. Like famotidine, DL and MeDL decreased the gastric acidity from 376.17+/-21.47 mequiv./l to 163.88+/-6.86 and 201.48+/-8.86 mequiv./l respectively in pyloric ligation model. These extracts increased the gastric pH without affording any protection to gastric mucosa in this model.

CONCLUSION

The latex of Calotropis procera has the therapeutic potential to relieve gastric hyperacidity and to prevent gastric ulceration induced by necrotizing agents.

Drought acclimation reduces O2− accumulation and lipid peroxidation in wheat seedlings

Abiotic stresses cause ROS accumulation, which is detrimental to plant growth. It is well known that acclimation of plants under mild or sub-lethal stress condition leads to development of resistance in plants to severe or lethal stress condition. The generation of ROS and subsequent oxidative damage during drought stress is well documented in the crop plants. However, the effect of drought acclimation treatment on ROS accumulation and lipid peroxidation has not been examined so far. In this study, the effect of water stress acclimation treatment on superoxide radical (O(2)(-z.rad;)) accumulation and membrane lipid peroxidation was studied in leaves and roots of wheat (Triticum aestivum) cv. C306. EPR quantification of superoxide radicals revealed that drought acclimation treatment led to 2-fold increase in superoxide radical accumulation in leaf and roots with no apparent membrane damage. However under subsequent severe water stress condition, the leaf and roots of non-acclimated plants accumulated significantly higher amount of superoxide radicals and showed higher membrane damage than that of acclimated plants. Thus, acclimation-induced restriction of superoxide radical accumulation is one of the cellular processes that confers enhanced water stress tolerance to the acclimated wheat seedlings.

Relative efficacy of three medicinal plant extracts in the alteration of thyroid hormone concentrations in male mice

Relative importance of Bacopa monnieri (200 mg/kg), Aegle marmelos (1.00 g/kg) and Aloe vera (125 mg/kg) leaf extracts in the regulation of thyroid hormone concentrations in male mice was investigated. While serum levels of both T(3) and T(4) were inhibited by A. vera, A. marmelos extract could decrease only T(3) concentration. On the other hand, T(4) concentration was increased by B. monnieri extract suggesting its thyroid-stimulating role. When the relative potency of each plant extract was calculated in terms of percent increase or decrease in thyroid hormones, as compared to the control value, the decrease in T(3) concentration by A. marmelos was about 62% indicating its possible use in the regulation of hyperthyroidism. B. monnieri could increase T(4) concentration by 41% without enhancing hepatic lipid peroxidation (LPO) suggesting that it can be used as a thyroid-stimulating drug. In fact, hepatic LPO was decreased and superoxide dismutase (SOD) and catalase (CAT) activities were increased by B. monnieri and A. marmelos leaf extracts showing their antiperoxidative role. It is thus suggested that A. marmelos and A. vera may be used in the regulation of hyperthyroidism, while B. monnieri in hypothyroidism.

Hypospadias-hypertelorism syndrome

A young male child presented with hypospadias. Examination revealed additional anomalies including hypertelorism and upslanting of palpebral fissures, suggesting a diagnosis of hypospadias-hypertelorism syndrome. The case is reported because of its rarity and some unusual features.

Inorganic anions induce state changes in spinach thylakoid membranes

The role of cations in excitation energy distribution between the two photosystems of photosynthesis is well established. This paper provides evidence, for the first time, for an important role of anions in the regulation of distribution of absorbed light energy between the two photosystems. Inorganic anions caused redistribution of energy more in favour of photosystem I, as judged from measurements of chlorophyll a fluorescence transients, rates of electron transport in low light and 77 K fluorescence emission spectra: the Fv/Fm ratio was decreased by inorganic anions even in the presence of DCMU, the PS II electron transport was decreased whereas PS I electron transport was increased and the F735 (77 K emission from PS I)/F685 (77 K emission from PS II) ratio was increased. Such changes were observed with inorganic anions having different valencies (Cl- , SO4(2-), PO4(3-)): the higher the valency of the inorganic anion, the more the energy transferred towards PS I. Change in the valency of the inorganic anions thus regulates distribution of absorbed light energy between the two photosystems. However, organic anions like acetate, succinate, and citrate caused no significant changes in the Fv/Fm ratio, and in rates of PS I and PS II electron transport, showing their ineffectiveness in regulating light energy distribution.

Electron spin resonance study of the metal binding site of glucose specific peripheral blood lymphocyte lectin

The electron spin resonance (ESR) spectrum of Mn2+ is highly responsive to changes in coordination symmetry. We have thus used ESR spectroscopy to study Mn2+ bound to goat peripheral blood lymphocyte lectin to delineate the nature of the metal binding site of the lectin. Our results suggest the presence of two metal binding sites on goat peripheral blood lymphocyte lectin, one a dissociable site which could bind Cu2+, Ca2+, Mg2+ and Ni2+ to displace bound Mn2+ and the other a non-dissociable site from which bound Mn2+ could not be displaced. Since no spectral changes are observed when D-glucose is bound, it is unlikely that Mn2+ participates directly in saccharide binding.

Mg(2+)-induced lipid phase transition in thylakoid membranes is reversed by anions

Effect of anions on thylakoid membrane fluidity as measured by rotational correlation time, order parameter (by ESR spectroscopy) and fluorescence polarization was studied. The data in the present study offer proof that Mg(2+)-induced rigidity of thylakoid membranes could be reversed by anions like bicarbonate and chloride. Anions were found to play a role in structural reorganization of thylakoid membranes.

ABA-induced 'lipid melting' and its reversal by umbelliferone in the plasmalemma of guard cell protoplasts: a breakthrough in plant hormone-receptor binding and hormone action

The dynamics of stomatal opening and closure had to date been ascribed largely to the K(+)-fluxes and cell wall elasticity. Using protoplasts of guard cells of Vicia faba as model system, we document convincing first hand evidence a that lipid phase alterations could regulate ABA-induced closure of stomates and its reversal by umbelliferone. Backed up by the presence of plasmalemma-located ABA-receptor in guard cells, a novel theory could be put forth explaining guard cell opening and closure mediated by hormone induced reconfiguration via a probable lipid-protein lattice modification. The phase reversal of the plasmalemma by umbelliferone is postulated to be through modified hormone receptor complex structure, which is yet to be substantiated.

Effect of cycocel and furfuryl amino purine on protein metabolism of pearl millet (Pennisetum americanum L.) under simulated drought conditions

Water stress drastically decreased relative water content and total soluble protein whereas it increased free amino acids, proline and protease enzyme in P. americanum. Treatments with 6-furfuryl amino purine (0.50 mM) and cycocel (60 mM) maintained the levels of soluble protein contents but the applications of furfuryl amino purine decreased free amino acids and free proline under stress conditions.

Discovery of a novel and alternate hydrogen peroxide generation machinery in the mammalian thyroid gland that modulates iodination of tyrosine

The hydrogen peroxide-dependent and peroxidase-mediated iodination of tyrosine, a pivotal step in the thyroxine biosynthesis in thyroid glands of mammals, has always been thought to be dependent on a glucose-glucose oxidase system to meet its demand for hydrogen peroxide. This report documents a novel and probably kinetically faster hydrogen peroxide-generating system operating in the thyroid gland cells involving the superoxide dismutase and superoxide anion radical. In the female cycling mice, the superoxide radical and superoxide dismutase activity are shown to be at persistently high levels, quite likely acting as a potent hydrogen peroxide synthesizer in the mammalian thyroid gland. The significance of this discovery in relation to the thyroid physiology is discussed.