Chitosan-based scaffolds as drug delivery systems in bone tissue engineering

The bone tissue engineering approach for treating large bone defects becomes necessary when the tissue damage surpasses the threshold of the inherent regenerative ability of the human body. A myriad of natural biodegradable polymers and scaffold fabrication techniques have emerged in the last decade. Chitosan (CS) is especially attractive as a bone scaffold material to support cell attachment and proliferation and mineralization of the bone matrix. The primary amino groups in CS are responsible for properties such as controlled drug release, mucoadhesion, in situ gelation, and transfection. CS-based smart drug delivery scaffolds that respond to environmental stimuli have been reported to have a localized sustained delivery of drugs in the large bone defect area. This review outlines the recent advances in the fabrication of CS-based scaffolds as a pharmaceutical carrier to deliver drugs such as antibiotics, growth factors, nucleic acids, and phenolic compounds for bone tissue regeneration.

Scientific advisory on nocturnal hypoglycemia in insulin-treated patients with diabetes: Recommendations from Indian experts

INTRODUCTION

Insulin is one of the commonly prescribed glucose lowering agents in diabetes. Hypoglycemia is the most common complication, and severe hypoglycemia is the most serious complication of insulin therapy. Almost half of all severe hypoglycemia episodes (HEs) occur at night. However, patients are often unaware of their nocturnal hypoglycaemia (NH) risk. Additionally, both healthcare professionals and patients find it difficult to manage NH. The purpose of this expert group meeting is to improve NH awareness and provide guidance for the physicians to recognize and manage NH.

METHOD

The panel of experts in an e-board deliberated extensively upon the available literature and guidelines on hypoglycemia and NH discussed the consensus on definition, detection, reporting, monitoring, treatment, and optimization of therapy in NH.

RESULT

& Conclusion: Though there are many guidelines on the management of HEs in patients with diabetes, very few touch the topic of NH. This scientific advisory on management of NH in insulin treated patients with diabetes is formulated to address this gap in understanding regarding management of NH. The experts provide recommendations for the nocturnal window, defining NH based on blood glucose values, recognition, prevention and management of NH.

Role of serum ferritin as a prognostic marker in acute ischemic stroke: A preliminary observation

Background:

Acute ischemic stroke is an important cause of morbidity and mortality. Search has been on to find out the factors which can help in formulating the prognosis of acute ischemic stroke. One of the prognostic indicators, which has gained great clinical interest in recent times, is serum ferritin.

Aims:

To assess the serum ferritin levels in patients with acute ischemic stroke and to study the role of serum ferritin as a prognostic marker in these patients.

Materials and Methods:

This prospective, observational study was conducted on 50 patients of acute ischemic stroke aged ≥18 years who presented within 48 hours of onset of symptoms. Clinical severity of stroke was assessed at admission and on the 6^th day using Canadian Stroke Scale (CSS), and serum ferritin levels were measured at admission and on the 6^th day in all these subjects.

Results:

The mean serum ferritin levels at admission in patients with “more severe stroke” (CSS score at admission ≤7) and “less severe stroke” (CSS score at admission >7) were 282.77 ± 120.53 and 205.12 ± 110.96 ng/mL, respectively. The mean serum ferritin levels at admission were 173.71 ± 109.69 ng/mL in subjects who did not deteriorate and 336.86 ± 57.28 ng/mL in those who deteriorated, while the mean serum ferritin levels on the 6^th day were 193.29 ± 101.88 and 343.95 ± 52.34 ng/mL in subjects who did not deteriorate and those who deteriorated, respectively.

Conclusions:

Serum ferritin has a significant positive correlation with the severity of acute ischemic stroke (P < 0.001), and the levels correlate with the outcome of the disease (P < 0.001); the patients with higher serum ferritin at admission tend to deteriorate more as compared to those with lower levels. Thus, serum ferritin can be used as a prognostic marker in acute ischemic stroke.

Collateral Development and Arteriogenesis in Hindlimbs of Swine After Ligation of Arterial Inflow

BACKGROUND

Development of collateral vasculature is key in compensating for arterial occlusions in patients with peripheral artery disease (PAD). We aimed to examine the development of collateral pathways after ligation of native vessels in a porcine model of PAD.

METHODS

Right hindlimb ischemia was induced in domestic swine (n = 11) using two versions of arterial ligation. Version 1 (n = 6) consisted of ligation with division of the right external iliac, profunda femoral, and superficial femoral arteries. Version 2 (n = 5) consisted of the ligation of version 1 with additional ligation with division of the right internal iliac artery. Development of collateral pathways was evaluated with standard angiography before arterial ligation and at termination (30 days later). Relative luminal diameter of the arteries supplying the ischemic right hind limb were determined by two-dimensional angiography.

RESULTS

The dominant collateral pathway that developed after version 1 ligation connected the right internal iliac artery to the right profunda femoral and then to the right superficial femoral and popliteal artery. Mean luminal diameter of the right internal iliac artery at termination increased by 38% compared with baseline. Two codominant collateral pathways developed in version 2 ligation: (i) from the left profunda femoral artery to the reconstituted right profunda femoral artery and (ii) from the common internal iliac trunk and the left internal iliac artery to the reconstituted right internal iliac artery, which then supplied the right profunda femoral and then the right superficial femoral and popliteal artery. The mean diameter of the left profunda and the left internal iliac artery increased at termination by 26% and 21%, respectively (P < 0.05).

CONCLUSIONS

Two versions of hindlimb ischemia induction (right ilio-femoral artery ligation with and without right internal iliac artery ligation) in swine produced differing collateral pathways, along with changes to the diameter of the inflow vessels (i.e., arteriogenesis).

Synthesis and biological evaluation of (-)-kunstleramide and its derivatives

Stereoselective total synthesis of (-)-kunstleramide, a cytotoxic dienamide from the bark of Beilschmiedia kunstleri gamble, has been accomplished by using Keck's asymmetric allylation and Trost isomerization as key reactions. Application of the developed strategy for the synthesis of a series of amide analogues (8-22) was also reported. Furthermore, the synthesized compounds were evaluated for their in vitro anti-proliferative activities against human epithelial lung carcinoma (A549), human epithelial cervical cancer (HeLa), human breast adenocarcinoma (MCF7) and human neuroblastoma (IMR32) cell lines using the SRB assay. All the compounds show moderate anti-proliferative activity against all cell lines. Some of the piperazine derivatives (17-22) strongly inhibit the growth of breast cancer cells with IC50 values of 8-20 μM.

Protective effects of recombinant glycoprotein D based prime boost approach against duck enteritis virus in mice model

Duck virus enteritis, also known as duck plague, is an acute herpes viral infection of ducks caused by duck enteritis virus (DEV). The method of repeated immunization with a live attenuated vaccine has been used for the prevention and control of duck enteritis virus (DEV). However, the incidence of the disease in vaccinated flocks and latency reactivation are the major constraints in the present vaccination programme. The immunogenicity and protective efficacy afforded by intramuscular inoculation of plasmid DNA encoding DEV glycoprotein D (pCDNA-gD) followed by DEV gD expressed in Saccharomyces cerevisia (rgD) was assessed in a murine model. Compared with mice inoculated with DNA (pCDNA-gD) or protein (rgD) only, mice inoculated with the combination of gD DNA and protein had enhanced ELISA antibody titers to DEV and had accelerated clearance of virus following challenge infection. Furthermore, the highest levels of lymphocyte proliferation response, IL-4, IL-12 and IFN-γ production were induced following priming with the DNA vaccine and boosting with the rgD protein. For instance, the specially designed recombinant DEV vector vaccine would be the best choice to use in ducks. It offers an excellent solution to the low vaccination coverage rate in ducks. We expect that the application of this novel vaccine in the near future will greatly decrease the virus load in the environment and reduce outbreaks of DEV in ducks.

Adaptation and growth kinetics study of an Indian isolate of virulent duck enteritis virus in Vero cells

Duck virus enteritis, also known as duck plague, is a viral infection of ducks caused by duck enteritis virus (DEV). The control of the disease is mainly done by vaccination with chicken embryo adapted live virus that is known to be poorly immunogenic and elicits only partial protection. Further, the embryo propagated vaccine virus pose a threat of harboring other infectious agents. Seeing these limitations, the present study reports for the first time regarding propagation and adaptation of a virulent Indian isolate of duck enteritis virus in Vero cell line. In this study isolation of an outbreak virus from Kerala state was done in chicken embryo fibroblast cell culture (CEF). Then adapted the DEV isolate in the Vero cell line. The characteristic cytopathic effects (CPE) of clumping and fusion of Vero cells were observed starting from the 7th passage onwards. The presence of the virus and its multiplication in Vero cells was confirmed by detection of viral specific DNA and antigen by using polymerase chain reaction (PCR) and indirect immuno fluorescent assay (IIFA), respectively. PCR detection of DEV using self designed primers for US4 (gD) and UL30 (DNA Polymerase) gene has been reported for the in the present study. The kinetics of DEV in Vero cells revealed a maximum infectivity titer of 10(5.6) TCID 50/ml after 48hr of viral infection. Compared to chicken embryo adapted DVE vaccine virus, the Vero cell culture system is free from other infectious agents. So it will be a good candidate for cultivation and propagation of duck enteritis virus vaccine strain. Further research studies are suggested to explore the feasibility of utilizing this Vero cell culture adapted DEV isolate for developing an attenuated vaccine virus against duck virus enteritis.

Pharmacological characterization of LPS and opioid interactions at the toll-like receptor 4

BACKGROUND AND PURPOSE

Previous work in our laboratory showed opioid agents inhibit cytokine expression in astrocytes. Recently, Watkins and colleagues hypothesized that opioid agonists activate toll-like receptor 4 (TLR4) signalling, which leads to neuroinflammation. To test this hypothesis, we characterized LPS and opioid effects on TLR4 signalling in reporter cells.

EXPERIMENTAL APPROACH

NF-κB reporter cells expressing high levels of TLR4 were used to compare LPS and opioid effects on NF-κB activation, a pathway activated by TLR4 stimulation.

KEY RESULTS

LPS increased TLR4 signalling in a concentration-dependent manner and was antagonized by LPS antagonist (LPS-RS, from Rhodobacter sphaeroides). A concentration ratio analysis showed that LPS-RS was a competitive antagonist. The opioid agonists, morphine and fentanyl, produced minor activation of TLR4 signalling when given alone. When tested following LPS stimulation, opioid agonists inhibited NF-κB activation but this inhibition was not blocked by the general opioid antagonist, naloxone, nor by the selective μ opioid receptor antagonist, β-FNA. Indeed, both naloxone and β-FNA also inhibited NF-κB activation in reporter cells. Further examination of fentanyl and β-FNA effects revealed that both opioid agents inhibited LPS signalling in a non-competitive fashion.

CONCLUSIONS AND IMPLICATIONS

These results show that LPS-RS is a competitive antagonist at the TLR4 complex, and that both opioid agonists and antagonists inhibit LPS signalling in a non-competitive fashion through a non-GPCR, opioid site(s) in the TLR4 signalling pathway. If confirmed, existing opioid agents or other drug molecules more selective at this novel site may provide a new therapeutic approach to the treatment of neuroinflammation.

Marker-assisted breeding as next-generation strategy for genetic improvement of productivity and quality: can it be realized in cotton?

The dawdling development in genetic improvement of cotton with conventional breeding program is chiefly due to lack of complete knowledge on and precise manipulation of fiber productivity and quality. Naturally available cotton continues to be a resource for the upcoming breeding program, and contemporary technologies to exploit the available natural variation are outlined in this paper for further improvement of fiber. Particularly emphasis is given to application, obstacles, and perspectives of marker-assisted breeding since it appears to be more promising in manipulating novel genes that are available in the cotton germplasm. Deployment of system quantitative genetics in marker-assisted breeding program would be essential to realize its role in cotton. At the same time, role of genetic engineering and in vitro mutagenesis cannot be ruled out in genetic improvement of cotton.

A neo-clerodane diterpene from Teucrium tomentosum. Corrigendum

Corrigendum to Acta Cryst. (2004), E60, o117–o119.

The chemical name of the title compound in the paper by Devi, Malathi, Rajan, Aravind, Krishnakumari & Ravikumar [Acta Cryst. (2004), E60, o117–o119] is corrected and the structural diagram is updated.

The Antioxidants in Prevention of Cataracts Study: effects of antioxidant supplements on cataract progression in South India

AIM

To determine if antioxidant supplements (beta carotene and vitamins C and E) can decrease the progression of cataract in rural South India.

METHODS

The Antioxidants in Prevention of Cataracts (APC) Study was a 5 year, randomised, triple masked, placebo controlled, field based clinical trial to assess the ability of interventional antioxidant supplements to slow cataract progression. The primary outcome variable was change in nuclear opalescence over time. Secondary outcome variables were cortical and posterior subcapsular opacities and nuclear colour changes; best corrected visual acuity change; myopic shift; and failure of treatment. Annual examinations were performed for each subject by three examiners, in a masked fashion. Multivariate modelling using a general estimating equation was used for analysis of results, correcting for multiple measurements over time.

RESULTS

Initial enrolment was 798 subjects. Treatment groups were comparable at baseline. There was high compliance with follow up and study medications. There was progression in cataracts. There was no significant difference between placebo and active treatment groups for either the primary or secondary outcome variables.

CONCLUSION

Antioxidant supplementation with beta carotene, vitamins C and E did not affect cataract progression in a population with a high prevalence of cataract whose diet is generally deficient in antioxidants.

Antifeedant neo-clerodanes from Teucrium tomentosum Heyne. (Labiatae)

From the acetone extract of Teucrium tomentosum, a new antifeedant neo-clerodane diterpenoid teuctosin (1) was isolated along with teuflin (2), teucrin-H(2) (3), 6beta-hydroxyteuscordin (4), 6beta-acetylteuscordin (5) and montanin-D (6). The structure of the new compound was elucidated comprehensively using 1D and 2D NMR methods and confirmed by X-ray crystallography. All the compounds showed effective antifeedancy against Plutella xylostella and Spodoptera litura at 10 mug/cm(2) of leaf area.

A new clerodane diterpene with antifeedant activity from Teucrium tomentosum

A new diterpene, viz. 3beta-acetoxy-4alpha,18:15,16-diepoxy-6beta,12-dihydroxyneocleroda-13(16),14-dien-19,20-olide, C(22)H(28)O(8), exhibiting antifeedant activity against Spodoptera litura was isolated from the aerial parts of Teucrium tomentosum and its structure is reported. One of the two fused rings has a distorted-chair conformation and the other has a chair conformation. The molecules in the crystal are stabilized via O--H...O and C--H...O hydrogen bonds.

Zaluzanin D: a fungistatic sesquiterpene from Vernonia arborea

Zaluzanin D, a sesquiterpene lactone has been isolated from the aerial parts of Vernonia arborea as a major constituent (0.04%). Antifungal activity of zaluzanin D has been studied against six plant-pathogenic fungi.

Microbial transformation of zaluzanin-D

Microbial transformation of zaluzanin-D using different fungi gave 11,13-dihydrozaluzanin-C, zaluzanin-C, 4,16,11,13 - tetrahydro zaluzanin-C, estafiatone, dihydroestafiatol and dihydroestafiatone.

Antifeedant and growth inhibitory effects of some neo-clerodane diterpenoids isolated from Clerodendron species (Verbenaceae) on Earias vitella and Spodoptera litura

Antifeedant and growth inhibitory effects of various neo-clerodane diterpenoids having a furofuran moiety, isolated from Clerodendron spp., were studied using Earias vitella and Spodoptera litura. The compounds clerodendrin B, 3-epicaryoptin, 15-hydroxyepicaryoptin, and clerodin were effective antifeedants at 10 microg/cm(3) (30 microg/g) of diet against E. vitella and at 10 microg/cm(2) of leaf against S. litura. All of the tested compounds, namely, clerodendrin B, 3-epicaryoptin, clerodendrin C, 15-hydroxyepicaryoptin, clerodendrin B acetate, and clerodin, showed good insect growth inhibitory activity even at lower concentrations.

Behavioural intervention in the management of compliance in young type-I diabetics

OBJECTIVES

a) To examine the efficacy of a behavioural intervention programme in the management of compliance in young Type I diabetics, b) To examine the efficacy of a behavioural management programme in enhancing metabolic control in young Type I diabetics, c) To examine the effect of behavioural intervention on level of diabetes knowledge and quality of life in young Type I diabetics.

METHODS

A total of 40 patients (Experimental group n = 20, Control group n = 20) was selected from local hospitals' pediatric, endocrinology and diabetology units. The experimental group received 15 individual sessions of behavioural intervention, consisting of behavioural counseling for family and significant others, relaxation, diabetes education and specific behavioural and cognitive strategies such as reinforcement, target-setting and cognitive restructuring. Assessment was carried out on various psychological measures as well as the glycosylated hemoglobin test (HbA1), at pre and post treatment periods.

RESULTS

The scores of the two groups were compared at post treatment point. Results indicate that there was significant improvement in the experimental group in compliance and metabolic control. There were also significant changes noted in the level of diabetes knowledge as well as the reported quality of life. These changes in compliance and metabolic control were maintained at a three month follow-up period.

CONCLUSIONS

Behavioural intervention can be included as an effective adjunct to routine medical care in the management of young Type I diabetics, especially in the management of compliance and metabolic control, enhancement of knowledge and quality of life.

Polyethylene glycol (PEG) modified bovine pericardium as a biomaterial: a comparative study on immunogenicity

Bioprosthetic heart valves made from glutaraldehyde (GA)-fixed porcine aortic valves or bovine pericardium (BP) are having some advantages over mechanical valves. However, their durability is low due to the calcification and immunological rejection. Study on immunogenicity is an important part in understanding the biocompatibility of materials. Polyethylene glycol (PEG) on pericardium can control biodegradation and calcification. Also, PEG exhibits low immunogenicity. We have studied the complement activation potential and the contribution of complement factors (biologic factors) on the calcification of PEG grafted pericardium samples and compared with standard (control) glutaraldehyde-treated pericardium samples. PEG-grafted BP activated using GA and carbodiimide (EDC) could be selected for further studies since complement activation and calcification observed on these samples has been relatively low.

Simultaneous intracellular and extracellular pH measurement in the heart by 19F NMR of 6-fluoropyridoxol

6-Fluoropyridoxol (6-FPOL) was evaluated as a simultaneous indicator of intracellular and extracellular pH and, hence, pH gradient in perfused rat hearts. After infusion, 19F NMR spectra rapidly showed two well-resolved peaks assigned to the intracellular and extracellular compartments, and pH was calculated on the basis of chemical shift with respect to a sodium trifluoroacetate standard. To demonstrate use of this molecule, dynamic changes in myocardial pH were assessed with a time resolution of 2 min during respiratory and metabolic alkalosis or acidosis and ischemia. For a typical heart, intracellular pH (pHi) = 7.14+/-0.01 and extracellular pH (pHe) = 7.52+/-0.02. In response to metabolic alkalosis, pHi remained relatively constant and the pH gradient increased. In contrast, respiratory challenge caused a significant increase in pHi. Independent measurements using pH electrodes and 31P NMR confirmed validity of the 19F NMR results.

Hyperacuity test to evaluate vision through dense cataracts; research preliminary to a clinical study. IV. Data on patients with macular degeneration and minimal media disorders obtained with and without a pseudo-nuclear cataract 6/60 (20/200) at the Aravind Eye Hospital, Madurai, India

Using a recently discussed three-point Vernier alignment test, data were obtained on patients with macular dysfunctions with and without a pseudo-nuclear cataract 6/60 (20/200) at the Aravind (Free) Eye Hospital, Madurai, India. The pseudo-cataract caused measurably and predictably reduced Vernier alignment thresholds, and necessary modifications deemed to be necessary in the protocol for later study are defined.

Hyperacuity test to evaluate vision through dense cataracts; research preliminary to a clinical study. III. Data on normal subjects obtained with and without a pseudo-nuclear cataract 6/60 (20/200) at the Aravind Eye Hospital, Madurai, India

Using a recently discussed three-point Vernier alignment test, data were obtained on normal subjects with and without a pseudo-nuclear cataract 6/60 (20/200) at the Aravind Eye Hospital, Madurai, India. This experiment is a critical control exercise. The pseudo-cataract caused measurably and predictably reduced Vernier alignment thresholds, there were no meaningful differences between eyes, and necessary modifications in protocol for a later clinical study were defined.

6-Fluoropyridoxol: a novel probe of cellular pH using 19F NMR spectroscopy

6-Fluoropyridoxol was evaluated as an intracellular pH indicator. This molecule exhibits exceptional sensitivity to changes in pH (approximately 10 ppm acid/base shift) and a pKa approximately 8.2 appropriate for physiological investigations. Using 19F NMR spectroscopy we determined both intra- and extracellular pH in whole blood and confirmed the measurements using traditional techniques: ion-electrodes and 31P NMR spectroscopy.