Poly(d,l-lactide-co-glycolide) Surface-Anchored Biotin-Loaded Irinotecan Nanoparticles for Active Targeting of Colon Cancer

A poly(d,l-lactide-co-glycolide) (PLGA) copolymer was synthesized using the ring-opening polymerization of d,l-lactide and glycolide monomers in the presence of zinc proline complex in bulk through the green route and was well characterized using attenuated total reflectance-Fourier transform infrared, 1H and 13C nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, X-ray diffraction, matrix-assisted laser desorption/ionization time-of-flight, etc. Furthermore, PLGA-conjugated biotin (PLGA-B) was synthesized using the synthesized PLGA and was employed to fabricate nanoparticles for irinotecan (Ir) delivery. These nanoparticles (PLGA-NP-Ir and PLGA-B-NP-Ir) were tested for physicochemical and biological characteristics. PLGA-B-NP-Ir exhibited a stronger cellular uptake and anticancer activity as compared to PLGA-NP-Ir in CT-26 cancer cells (log p < 0.05). The accumulation and retention of fluorescence-labeled nanoparticles were observed to be better in CT-26-inoculated solid tumors in Balb/c mice. The PLGA-B-NP-Ir-treated group inhibited tumor growth significantly more (log p < 0.001) than the untreated control, PLGA-NP-Ir, and Ir-treated groups. Furthermore, no body weight loss, hematological, and blood biochemical tests demonstrated the nanocarriers' nontoxic nature. This work presents the use of safe PLGA and the demonstration of a proof-of-concept of biotin surface attached PLGA nanoparticle-mediated active targeted Ir administration to combat colon cancer. To treat colon cancer, PLGA-B-NP-Ir performed better due to specific active tumor targeting and greater cellular uptake due to biotin.

In situ assembly of bioresorbable organic bioelectronics in the brain

Bioelectronics can potentially complement classical therapies in nonchronic treatments, such as immunotherapy and cancer. In addition to functionality, minimally invasive implantation methods and bioresorbable materials are central to nonchronic treatments. The latter avoids the need for surgical removal after disease relief. Self-organizing substrate-free organic electrodes meet these criteria and integrate seamlessly into dynamic biological systems in ways difficult for classical rigid solid-state electronics. Here we place bioresorbable electrodes with a brain-matched shear modulus-made from water-dispersed nanoparticles in the brain-in the targeted area using a capillary thinner than a human hair. Thereafter, we show that an optional auxiliary module grows dendrites from the installed conductive structure to seamlessly embed neurons and modify the electrode's volume properties. We demonstrate that these soft electrodes set off a controlled cellular response in the brain when relaying external stimuli and that the biocompatible materials show no tissue damage after bioresorption. These findings encourage further investigation of temporary organic bioelectronics for nonchronic treatments assembled in vivo.

Modelling the growth curve and estimation of associated genetic parameters in Munjal sheep

The study of growth curves in sheep is an effective approach to monitor the animal development for predicting the growth rate and improving overall flock performance. The purpose of the present work was to study the growth curve traits of Munjal sheep using different non-linear models and to estimate the genetic parameters of those traits for the possibility of inclusion of them under selection strategy. Total 2285 weight records at birth, 3, 6 and 12 months of age of 706 lambs born to 48 sires and 149 dams were collected from the registers maintained from 2004 to 2019. Various non-linear growth models viz., Brody, Gompertz, logistic, Bertalanffy and negative exponential were fitted to targeted growth curve traits and then evaluated using goodness of fit criteria such as adjusted R², root means square error (RMSE), Akaike's information criterion (AIC) and Bayesian information criterion (BIC). The genetic parameters of growth curve traits were estimated using animal model. The results suggested that Brody model was best fitted to the data than other models. The growth curve estimates for mature weight (A), inflexion point (B) and rate of maturation (k) under Brody model were 25.82 ± 1.72, 0.84 ± 0.04, and 0.21 ± 0.04, respectively for female lambs, and 29.55 ± 2.04, 0.86 ± 0.03 and 0.19 ± 0.04, respectively for male lambs. The males showed superiority for mature weights whereas female lambs had higher maturation rates. The estimates of direct heritability for A, B and k were 0.33, 0.41 and 0.10, respectively. The moderate estimate of direct heritability of A and its negative genetic correlation with k indicated the scope of genetic improvement through selection based on mature weights. Therefore, it was concluded from the present findings that Brody model was the one that best describes the growth curve in the Munjal sheep and the selection based on mature weights can be employed for genetic improvement of Munjal flock.

Estimation of inbreeding and its effects on growth traits in Beetal goat

The purpose of the present study was to estimate the inbreeding coefficient and its effects on various growth traits in Beetal goat using pedigree records of 963 kids born to 38 sires and 287 dams over the period of 2004 to 2019. The inbreeding coefficients for each individual were obtained under animal model. The effects of inbreeding along with other fixed effects such as year of birth, sex of kid, type of birth, and dam's weight at kidding on growth traits viz., weight at birth (BWT), 3 (WT3), 6 (WT6), 9 (WT9), and 12 (WT12) months of age were studied using least-squares analysis. Additionally, average daily gain and Kleiber ratio up to weaning age (90 days) were studied under the same model. The overall inbreeding coefficient was low in magnitude (1.42%) and ranged from 0 to 25% over the study period. The significant (P < 0.05) increase in average inbreeding coefficient (%) over the years was observed among the studied population. Although, the effects of various factors had significant (P < 0.05) influence on growth traits under least-squares model, the regression of targeted traits on inbreeding were non-significant (P > 0.05) and the same ranged from - 0.06 to 0.04. The present findings indicated that there was no inbreeding depression among the growth traits of Beetal goat. However, as inbreeding (%) raised in recent years only, the scientific efforts must be taken to avoid inbreeding at resourced population by introducing new germplasms at earliest.

Neural network and Bayesian-based prediction of breeding values in Beetal goat

The estimation of breeding values is prime concern for animal breeders in order to achieve desired genetic progress of farm animals. However, current methods for estimating BV involve simultaneous selection of animal model which are computationally intensive and time-consuming. The present attempt was made to predict breeding values of weaning trait under artificial neural networks (ANN), Bayesian technique (BT), and multiple regression (MR) methods. The data records comprising year of birth, sex, type of birth, dam's weight at kidding, birth weight, weaning weight, and estimated breeding values (BV) for weaning weight (under animal model) pertaining to 849 kids born to 37 sires and 237 dams between 2004 and 2019 were used in this study. All three methods, viz., ANN under multilayer perceptron (2 hidden layers), BT under Markov chain Monte Carlo (MCMC) approach, and MR under full model, were used for 75% training dataset initially and prediction model developed was applied on 25% test dataset. The initial analysis showed positive and significant (P < 0.01) relationship of BV with other variables which hinted that BV may be predicted with accuracy. Then, it was revealed from the results indicated that ANN, BT, and MR methods have similar accuracy (r = 0.86 to 0.87) for prediction of BV. However, ANN showed slightly higher but negligible model adequacy than BT and MR method. The prediction error under three methods was almost equal. The results indicated that these methods could be used as potential alternative for recurrent prediction of BV based on phenotypic data in order to optimize selection plans at young age in resourced population of Beetal goat.

Investigation of cause-specific pre-weaning mortality in Harnali sheep

Lamb mortality is an important aspect in sheep production system which affects farm profitability worldwide. The aim of the present study was to investigate the causes of pre-weaning mortality (PWM) in Harnali lambs with respect to various associated factors. The data records of 173 lambs which died before 90 days of age (weaning age) out of 2057 lambs born during 2001-2020 year were collected from various registers, and the respective causes of mortality were taken from the post-mortem reports. The association of various factors such as age, sex, period of birth, birth weight of lamb and causes of death with PWM was assessed using chi-square test and log-linear modelling. The results showed that respiratory and digestive diseases were major causes of PWM. The log-linear modelling showed significant (P < 0.05) association of age, sex and period of birth with PWM. In the first month of age, digestive disease was the predominant cause of death; however, with age of lamb advances, respiratory disease was more prevalent. It was also revealed that male lambs (odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.24, 0.97) had lesser deaths due to respiratory diseases as compared to digestive disease. The reverse scenario was observed in female lambs. The findings of the present study might be helpful for understanding the risks and common causes of PWM in lambs to implement appropriate management practices in order to reduce economic losses to sheep farmers.

Meta-analysis of MspI derived variants of growth hormone gene associated with milk yield in dairy cattle

OBJECTIVE

The present work aimed to obtain common effect sizes for the gene frequency and association of MspI derived variants of growth hormone (GH) gene with milk yield in dairy cows.

METHODS

We performed a systematic review and meta-analysis of 35 published studies identified in literature search from 2000 to 2020 (n = 4164). These studies were specific to fragment size (329) for genotypes viz., CC (224, 105 bp), CD (329, 224, 105 bp) and DD (329 bp). Pooled standard mean differences (SMDs) as effect sizes between allele pairs were derived using different genetic models. The heterogeneity between effects sizes across studies was estimated using I² Index (%).

RESULTS

The common effect size for gene frequency of allele C (224, 105 bp) was significantly (P < 0.05) higher in 2881 Bos taurus/cross cows (0.82; 95% CI: 0.74, 0.89; I² = 97.81%) than 1283 Bos indicus cows (0.15; 95% CI: 0.12, 0.18; I² = 71.90%), with overall gene frequency was 0.33 (95% CI: 0.21, 0.46; I² = 99.29%). Additive (CC vs. DD) and dominant (CC + CD vs. DD) did not revealed significant (P > 0.05) association with milk yield. However, completely over dominant (CC + DD vs. CD) and recessive (CC vs. CD + DD) models showed significant (P < 0.05) and positive SMDs with milk yield specially at early lactations. There was no evidence of heterogeneity (I² = 0.00%) between SMDs across studies.

CONCLUSIONS

This meta-analysis suggested potential association of C allele for enhancing milk production of dairy cows.

Evaluation of candidate point mutation of Kisspeptin 1 gene associated with litter size in Indian Goat breeds and its effect on transcription factor binding sites

Kisspeptin gene (Kiss1) has a significant role in reproductive processes in mammals. However, only little information is available about the association of Kiss1 gene with litter size in Indian goat breeds. Thus, blood samples from 285 randomly selected animals were collected for DNA isolation and SNP profiling. The PCR product of 242 bp size harboring g.2540C>T mutation of Kiss1 gene was digested with the restriction enzyme Sac1. Least squares analysis revealed that Barbari goats showed significantly higher average litter size (2.86±0.08) compared to Beetal, Sirohi and Sojat breeds (P < 0.01). SNP locus g.2540C>T of Kiss1 gene also showed significant effect on litter size (P < 0.01). Goats with Genotype CT (2.66 ± 0.07) and TT (2.67 ± 0.26) had significantly higher (P < 0.01) litter size than CC (1.50 ± 0.05). From the transcription factor binding site analysis, it was predicted that due to g.2540C>T SNP, both native and mutant variant forms coded for putative binding sites for different transcription Factor. Allele T had putative binding sites for the androgen receptor which plays a significant role in the signaling pathway involved in increase in ovulation rate; which consequently can have a tremendous effect on average litter size.

Effect of BsaA I genotyped intronic SNP of leptin gene on production and reproduction traits in Indian dairy cattle

In the present study, candidate single nucleotide polymorphism (SNP) g.92450765 G > A of leptin gene was explored for Bos indicus cattle with an aim to explore its possible effect on production and reproduction traits. The genotypic and allelic frequencies of BsaA 1 genotyped SNP g.92450765 G > A indicated the predominance of AG (0.65) genotyped Sahiwal cows in our studied population. The least-squares analysis showed a significant association (p < 0.05) of identified genetic variants with total milk yield (TMY) and 305 days milk yield (MY) (p < 0.05). The GG genotyped cows were found to be associated with higher milk yields. However, for reproduction traits under study AA genotype was found to be more favorable with respect to service period and calving interval (p < 0.05). Computational analysis was also performed to predict changes if any in the transcription factor binding sites (TFBS) caused due to the identified SNP in the intronic region of the leptin gene. TFBS analysis predicted that the targeted SNP at g.92450765G > A may lead to the disappearance of TFBS such as Hypermethylated in cancer 2 protein (HIC2), Max-binding protein MNT (MNT), Cyclic AMP-dependent transcription factor -3 (ATF3), Myc-associated factor X (MAX) and Microphthalmia-associated transcription factor (MITF). It may lead to changes in transcriptional regulation.

Evaluating advanced computing techniques for predicting breeding values in Harnali sheep

Advanced computing techniques have been used by animal researchers to understand the intricate data structures for deriving the most reliable allusions of populations in order to conserve genetically superior animals. The present attempt was made to evaluate the potential of two advanced techniques, artificial neural networks (ANN) and Bayesian technique (BT), for predicting breeding values (BV) of weaning weight (WWT) using data of 498 lambs born to 41 sires and 173 dams in Harnali sheep for the period from 2014 to 2019. The estimated BV for WWT was initially obtained using univariate animal model under restricted maximum likelihood procedure. ANN using multilayer perceptron with two hidden layers was fitted to training set (75%) of estimated BV to predict BV for test set (25%). Similarly, BT using Markov chain Monte Carlo (MCMC) method was also fitted to similar datasets. The high accuracy of prediction, i.e., correlation between BV and predicted BV, was observed as 0.89 and 0.90 under ANN and BT, respectively. Further, similar ranges of goodness of fit criteria, viz., R², root mean square error (RMSE), mean absolute error (MAE), and bias, indicated that both ANN and BT had similar prediction ability, which was also confirmed by 10-fold cross-validation. The present study indicated high capability and analogous model adequacy for both techniques that can be exploited in selection programs.

Continuous flow fabrication of Fmoc-cysteine based nanobowl infused core-shell like microstructures for pH switchable on-demand anti-cancer drug delivery

Asymmetric nanostructures such as nanobowls (NBs) can exhibit superior drug delivery performances owing to their concave structure and interior asymmetric cavities. Here, we present a facile one-step method for the fabrication of NB like structures from a mere single amino acid mimetic, N-(9-fluorenylmethoxycarbonyl)-S-triphenylmethyl-l-cysteine following continuous-flow microfluidics enabled supramolecular self-assembly. Following fabrication, NBs were further infused into a vesicular shell consisting of the amino acid N-(tert-butoxycarbonyl)-S-triphenylmethyl-l-cysteine, carrying dual acid labile groups, the triphenylmethyl and the tert-butyloxycarbonyl groups. The NB infused core-shell like microstructures formed after the shell coating will now be addressed as NB-shells. Presence of pH-responsive shells bestowed the core-shell NB like structures with the ability to actively tune their surface pore opening and closing in response to environmental pH switch. To illustrate the potential use of the NB-shells in the field of anticancer drug delivery, the particles were loaded with doxorubicin (Dox) with an encapsulation efficiency of 42% and Dox loaded NB-shells exhibited enhanced efficacy in C6 glioma cells. Additionally, when tested in an animal model of glioblastoma, the nanoformulations demonstrated significantly higher retardation of tumour growth as compared to free Dox. Thus, this work strives to provide a new research area in the development of well turned-out and neatly fabricated pH switchable on/off anti-cancer drug delivery systems with significant translational potential.

Functional design of pH-responsive folate-targeted polymer-coated gold nanoparticles for drug delivery and in vivo therapy in breast cancer

BACKGROUND

Curcumin has been widely used owing to its various medicinal properties including antitumor effects. However, its clinical application is limited by its instability, poor solubility and low bioavailability. Folic acid (FA)-functionalized nanoformulations may enhance the sustained release of an anticancer drug (curcumin) by tumor-specific targeting to improve therapeutic benefit. This study aims to design a nanoconjugate (NC) comprised of folate-curcumin-loaded gold-polyvinylpyrrolidone nanoparticles (FA-CurAu-PVP NPs) for targeted delivery in breast cancer model systems.

METHODS

We developed curcumin-loaded FA-functionalized Au-PVP NCs by layer-by-layer assembly. The folic acid-curcumin Au-PVP NCs (FA-CurAu-PVP NCs) were characterized by ultraviolet-visible spectra, Fourier transform infrared spectroscopy, X-ray powder diffraction and thermogravimetric analysis. In vitro anticancer and antimigratory effects of NCs were examined by performing MTT and wound migration assays. The in vivo antitumor efficacy of NCs was investigated using a preclinical breast cancer orthotopic mouse model.

RESULTS

Curcumin (40 µg/mL) was loaded along with conjugation of folate onto Au-PVP NPs to form FA-CurAu-PVP NCs. The size and charge of the NCs were increased gradually through layer-by-layer assembly and showed 80% release of curcumin at acidic pH. The NC did not show aggregation when incubated with human serum and mimicked an intrinsic peroxidase-like property in the presence of 3,3',5,5'-tetramethylbenzidine substrate. The MTT data using these NCs showed efficient anticancer activity at lower doses in estrogen/progesterone receptor (ER/PR)-negative cells compared with ER/PR-positive cells. Furthermore, the NCs did not show cytotoxicity at the investigated concentration in human breast epithelial and mouse fibroblast cell lines. They showed inhibitory effects on cell migration and high antitumor efficacy in in vivo analysis.

CONCLUSION

These results suggest that folate-based tumor targeting using CurAu-PVP NCs is a promising approach for tumor-specific therapy of breast cancer without harming normal cells.

Receptor tyrosine kinases (RTKs) in breast cancer: signaling, therapeutic implications and challenges

Breast cancer is a multifactorial disease and driven by aberrant regulation of cell signaling pathways due to the acquisition of genetic and epigenetic changes. An array of growth factors and their receptors is involved in cancer development and metastasis. Receptor Tyrosine Kinases (RTKs) constitute a class of receptors that play important role in cancer progression. RTKs are cell surface receptors with specialized structural and biological features which respond to environmental cues by initiating appropriate signaling cascades in tumor cells. RTKs are known to regulate various downstream signaling pathways such as MAPK, PI3K/Akt and JAK/STAT. These pathways have a pivotal role in the regulation of cancer stemness, angiogenesis and metastasis. These pathways are also imperative for a reciprocal interaction of tumor and stromal cells. Multi-faceted role of RTKs renders them amenable to therapy in breast cancer. However, structural mutations, gene amplification and alternate pathway activation pose challenges to anti-RTK therapy.

Effect of antioxidants supplementation on the quality of Beetal buck semen stored at 4°C

Aim

An experiment was designed to evaluate the role of Vitamin E and glutathione in improving the seminal parameters during hypothermic storage of liquid semen at 4°C for 72 h.

Materials and Methods

Thirty-six semen ejaculates were collected by artificial vagina from 6 bucks (Beetal) during the normal reproduction season (September to November) at weekly interval. The samples were centrifuged, and the seminal plasma was removed. The sperm pellet was diluted with Tris-based extender and divided into three groups. Group T1: Control samples without antioxidants, Group T2: Samples supplemented with tocopherol at 3 mM, and Group T3: Samples supplemented with glutathione at 1 mM. The samples were evaluated for progressive motility, percent liveability, percent abnormal spermatozoa, and acrosome integrity after liquid preservation for 0, 24, 48, and 72 h. The level of lipid peroxidation and antioxidant enzymes, namely, glutathione peroxidase (GPx) and superoxide dismutase (SOD) were estimated after liquid preservation for 0 and 72 h.

Results

It was observed that, after storage of semen at 4°C up to 72 h, the progressive sperm motility, percent liveability, percent abnormal spermatozoa, and percent intact acrosomes were significantly (p<0.05) higher in group T2 and T3 samples as compared to control. However, the level of lipid peroxidation in T2 and T3 groups was significantly (p<0.05) lower after 72 h of incubation at 4°C. Similarly, GPx and SOD values were significantly (p<0.05) increased in T2 and T3 groups after 72 h of storage at 4°C.

Conclusion

Thus, it can be concluded that Vitamin E and glutathione supplementation at 3 mM and 1 mM, respectively, while preserving the semen samples at 4°C helped in maintaining the seminal parameters up to 72 h and protected the spermatozoa from oxidative damage.

Relationship of plasma homocysteine with lipid profile parameters in ischemic heart disease

The present study was undertaken to explore the relationship of plasma homocysteine with other biochemical parameters in ischemic heart disease. Plasma levels of total homocysteine was measured by HPLC-fluorescence detection with internal standard in 60 ischemic heart disease patients and were compared with 30 age matched normal healthy controls. The significant increase of plasma homocysteine was observed in both myocardial infarction and chronic stable ischemic heart disease patients when compared with the controls. The hyperhomocysteinemia appears be to due to increased body demand of vitamins such as folic acid, vitamin B(12), B(6), B(2) either alone or in combination to regulate normal homocysteine metabolism.

Retinal blood flow abnormalities following six months of hyperglycemia in the Ins2(Akita) mouse

The aim of this study was to characterize the microvascular flow abnormalities and oxygenation changes that are present following six months of hyperglycemia in the diabetic Ins2(Akita) mouse. Previous studies have shown decreased retinal blood flow in the first several weeks of hyperglycemia in rodents, similar to the decreases seen in the early stages of human diabetes. However, whether this alteration in the mouse retina continues beyond the initial weeks of diabetes has yet to be determined, as are the potential consequences of the decreased flow on retinal oxygenation. In this study, male Ins2(Akita) and age-matched C57BL/6 (non-diabetic) mice were maintained for a period of six months, at which time intravital microscopy was used to measure retinal blood vessel diameters, blood cell velocity, vascular wall shear rates, blood flow rates, and transient capillary occlusions. In addition, the presence of hypoxia was assessed using the oxygen-sensitive probe pimonidazole. The diabetic retinal microvasculature displayed decreases in red blood cell velocity (30%, p<0.001), shear rate (25%, p<0.01), and flow rate (40%, p<0.001). Moreover, transient capillary stoppages in flow were observed in the diabetic mice, but rarely in the non-diabetic mice. However, no alterations were observed in retinal hypoxia as determined by a pimonidazole assay, suggesting the possibility that the decreases seen in retinal blood flow may be dictated by a decrease in retinal oxygen utilization.

Effect of tempol on diabetes-induced decreases in retinal blood flow in the mouse

PURPOSE

The purpose was to investigate the effect of the superoxide dismutase mimetic tempol on decreases in retinal blood flow that are found in diabetic mice.

MATERIALS AND METHODS

Streptozotocin (STZ) was injected into male C57BL/6 mice to induce hyperglycemia. One week following the STZ injection, subsets of the mice were given drinking water with or without 1 mM tempol for an additional three weeks. At the end of the four-week protocol, microvascular parameters were quantified via intravital microscopy, and included measurements of retinal diameters, red blood cell (RBC) velocities, blood flow rates, and wall shear rates.

RESULTS

Diabetes induced ~40-45% decreases in retinal blood flow rate (p < 0.001) four weeks following injection of STZ. The decrease in blood flow rate occurred with decreases in microvascular diameters (D) and RBC velocities (V). The average percentage decrease in velocity was greater than the percentage decrease in diameter and, therefore, wall shear rates (= 8 V/D) were ~25% lower in the diabetics than in the non-diabetics (p < 0.05). A three-week administration of tempol in the STZ mice allowed significantly higher blood flow rates than in the untreated STZ mice, with RBC velocities improved by the antioxidant (p < 0.05 on the venular side). However, tempol provided only moderate (and not statistically significant) improvements in wall shear rates.

CONCLUSIONS

The antioxidant tempol provides partial improvements in retinal microvascular hemodynamics early in the progression of STZ-induced diabetes in mice.

Response surface analysis of nano-ureases from Canavalia ensiformis and Cajanus cajan

Ureases isolated from leguminous sources, Canavalia ensiformis and Cajanus cajan were immobilized onto gold nanoparticles (nano-ureases). Optimization of the urease immobilization was carried using response surface methodology based on Central Composite Design. Immobilization efficiency of nano-urease from C. ensiformis and C. cajan were found to be 215.10% and 255.92%, respectively. The methodology adopted has deviation of 2.56% and 3.01% with respect to experimental values in case of C. ensiformis and C. cajan, respectively. Nano-urease from C. cajan has broad physico-chemical parameters with pH optimum from 7.1 to 7.3 and temperature optimum from 50 to 70°C. Nano-urease from C. ensiformis has sharp pH and temperature optima at 7.3 and 70°C, respectively. Fourier transform infra-red spectroscopy has revealed involvement of groups viz. amino, glycosyl moiety, etc. in urease immobilization onto gold nano-particles. Transmission and scanning electron micrographs revealed that arrangement of urease onto gold nano-particles from C. ensiformis was uniform while it was localized in case of C. cajan. Nano-urease from C. ensiformis has higher specificity and catalysis toward urea as compared to nano-urease from C. cajan. Nano-ureases from both sources are equally stable for 6 months under dried conditions and can be used for 10 washes.

Inhibition of 20-HETE attenuates diabetes-induced decreases in retinal hemodynamics

The mechanisms of early diabetes-induced decreases in retinal blood flow have yet to be fully determined. The aim of this study was to explore the hypothesis that 20-hydroxyeicosatetraenoic acid (20-HETE) plays a role in the early decrease of retinal hemodynamics in diabetic mice. 20-HETE has been implicated previously in the diabetes-enhanced vasoconstriction of mesenteric and renal vessels; however, its role in the diabetic retinal microcirculation has not been investigated. Diabetes was induced by multiple low-dose injections of streptozotocin (STZ; 50 mg/kg for 5 consecutive days), then ∼2 weeks later the mice were administered daily intraperitoneal injections with or without the 20-HETE inhibitor HET0016 (2.5 mg/kg/day) for the following 2 weeks. Non-diabetic age-matched mice were included as controls. Intravital microscopy was used to obtain measurements of retinal vascular diameters and red blood cell (RBC) velocities for the feed arterioles and draining venules extending out of and into the optic disk. From these values, wall shear rates and blood flow rates were calculated. Diabetes induced approximately 30-40% decreases in RBC velocity, wall shear rate, and blood flow rate. These decreases were attenuated to 5-10% in the mice given HET0016. In summary, the 20-HETE inhibitor HET0016 is able to attenuate the retinal hemodynamic changes induced by diabetes.

Relationship between inflammation and tissue hypoxia in a mouse model of chronic colitis

BACKGROUND

Hypoxia has been reported to be associated with the colonic inflammation observed in a chemically induced mouse model of self-limiting colitis, suggesting that low tissue oxygen tension may play a role in the pathophysiology of inflammatory tissue injury. However, no studies have been reported evaluating whether tissue hypoxia is associated with chronic gut inflammation. Therefore, the objective of the present study was to determine whether hypoxia is produced within the colon during the development of chronic gut inflammation.

METHODS

Adoptive transfer of CD4(+) T cells obtained from interleukin-10-deficient (IL-10(-/-)) mice into lymphopenic recombinase-activating gene-1-deficient (RAG(-/-)) mice induces chronic colonic inflammation, with the inflammation ranging from mild to severe as determined by blinded histological analyses. Colonic blood flow, hematocrit, and vascular density were determined using standard protocols, whereas tissue hypoxia was determined using the oxygen-dependent probe pimonidazole.

RESULTS

Adoptive transfer of IL-10(-/-) CD4(+) T cells into RAG(-/-) recipients induced chronic colonic inflammation that ranged from mild to severe at 8 weeks following T-cell transfer. The colitis was characterized by bowel wall thickening, goblet cell dropout, and inflammatory infiltrate. Surprisingly, we found that animals exhibiting mild colonic inflammation had increased hypoxia and decreased systemic hematocrit, whereas mice with severe colitis exhibited levels of hypoxia and hematocrit similar to healthy controls. In addition, we observed that the extent of hypoxia correlated inversely with hematocrit and vascular density.

CONCLUSIONS

Changes in hematocrit, vascular density, and inflammatory state appear to influence the extent of tissue oxygenation in the T-cell-mediated model of chronic gut inflammation.

Effect of pasteurization of shell egg on its quality characteristics under ambient storage

Three thermal processes viz. dry (55°C, 2 h), moist (57°C, 5 min) and microwave (power 9, 20 sec) were studied to determine their efficacy for the pasteurization of intact chicken eggs based on the extent of inactivation of artificially inoculated Salmonella typhimurium (ST) in the yolk of shell eggs and alteration in albumen protein solubility (APS). Moist heat treatment was superior to others as it brought about 2 log cfu/ml reduction of inoculated ST in much less time than dry heating but changes in APS were not significant. Subsequent quality evaluation of normal (uninoculated) eggs subjected to moist heat pasteurization during 15 days of ambient (35°C, 36% RH) (35 ± 0.5°C, 36 ± 2% RH)storage revealed no significant effect on percent loss in egg weight, albumen pH, viscosity of albumen and yolk and thiobarbituric acid values between pasteurized and unpasteurized eggs. Pasteurization had no adverse effect on foam volume and foam stability of albumen during storage in comparison to those of raw eggs. Naturally occurring aerobic mesophilic bacteria, coliforms, staphylococci, yeast and moulds on the egg shell surface and in egg contents got markedly reduced by pasteurization of shell eggs and their multiplication also retarded during storage. Both pasteurized and raw eggs remained fairly acceptable sensorily up to 10 days of storage at ambient conditions.

Attenuation of streptozotocin-induced microvascular changes in the mouse retina with the endothelin receptor A antagonist atrasentan

Hyperglycemia mediates endothelial cell dysfunction through a number of potential mechanisms that could result in the decrease of retinal blood flow early in diabetes. The aim of this study was to explore the role of endothelin receptor A (ET(A)) in the early decrease of retinal blood flow in diabetic mice. Diabetes was induced by streptozotocin, then ∼1 wk later the mice were administered drinking water with or without the ET(A) receptor antagonist atrasentan (7.5mg/kg/day) for the following 3 weeks. Non-diabetic age-matched mice with or without atrasentan were included as controls. For each mouse, measurements of retinal vascular diameters and red blood cell (RBC) velocities were obtained via intravital microscopy for the 5-7 feed arterioles (and draining venules) extending out of (and into) the optic disk, and from these values, flow rates and wall shear rates were calculated. Additionally, the number of retinal capillaries was counted by fluorescent immunostaining of platelet-endothelial cell adhesion molecule-1 (PECAM-1). Diabetes induced statistically significant decreases in RBC velocity, flow rate, and wall shear rate, with these alterations partially inhibited by atrasentan. No changes were observed in PECAM-1 expression among groups. The changes induced by diabetes, and the attenuation provided by atrasentan, were greater in the smaller retinal arterioles. In summary, ET(A) appears to play a role in the early decreases in retinal blood flow in a mouse model of diabetes.

Inhibition of iron induced lipid peroxidation and antioxidant activity of Indian spices and Acacia in vitro

The spices used in the Indian foods such as Star anise (Illicium verum), Bay leaves (Cinnamomum zeylanicum) and Cobra's saffron (Mesua ferrea), and Acacia (Acacia catechu), which have medicinal value, were used as test samples, to find their effect on in vitro lipid peroxidation (LPO). Rat liver post mitochondrial supernatant (PMS) in Tris HCl buffer, pH 7.4 was incubated for 0 and 1 h, with various test extracts in three different oxidant systems. The results show that addition of test samples to FeCl(3) medium at 0 h significantly stop the initiation of the LPO. However, the propagation phase of LPO was inhibited by Cobra's saffron and Acacia and not by Star anise and Bay leaves. The test samples also showed strong reducing power and superoxide radical scavenging activity. Cobra's saffron and Acacia showed the highest antioxidant activity, probably due to the higher polyphenol content as compared to other test samples.

Homocysteine, lipid indices and antioxidants in patients with ischaemic heart disease from Maharashtra, India

INTRODUCTION

Geographical and ethnic factors have recently been shown to have a significant role to play in cardiovascular diseases. The exact relationship between nutritional and geographical factors in cardiovascular diseases is not very clear. This study examined the relationship of hyperhomocysteinaemia with lipid profile and antioxidants in patients with ischaemic heart disease from rural areas in Maharashtra, India.

METHODS

Blood cholesterol (total, high- and low-density lipoproteins cholesterol), triglycerides along with thiobarbituric acid reactive substances (TBARS), superoxide dismutase, glutathione peroxidase and catalase activities were measured in acute coronary syndrome (ACS) and chronic stable angina (CSA) patients from rural areas and in normal healthy controls from the same area. Plasma total homocysteine was measured by high pressure liquid chromatography with fluorescence detection. Folic acid and vitamin B12 were measured by chemiluminescence immunoassay.

RESULTS

The relative lipid ratios were higher in the patients and had a poor correlation with antioxidants. Total homocysteine levels were significantly higher by almost three times more than the controls. TBARS levels also showed a similar pattern, whereas antioxidant enzymes showed a significantly greater fall in ACS than CSA. There was a definite inverse relationship between total homocysteine, TBARS and antioxidants in the patients. The levels of folic acid and vitamin B12 were 3-4 times higher in the patients compared to the controls. There was a poor correlation between the total homocysteine and vitamin levels in the patients.

CONCLUSION

Blood homocysteine is a very important biomarker of cardiovascular diseases and must be evaluated along with other risk factors. There is a higher prevalence of hyperhomocysteinaemia in rural Indian patients. There appears to be a strong association of genetic factors in the development of ischaemic heart disease in Indian patients.

Chemo-preventive effect of Star anise in N-nitrosodiethylamine initiated and phenobarbital promoted hepato-carcinogenesis

The generation of free radicals is a cause of many pathological conditions like diabetes mellitus, cancer, stroke, etc. Free radicals cause damage to cellular DNA and initiate carcinogenesis. Free radicals also bring about proliferation of cells via cell signaling. An inverse relationship between the consumption of vegetable diets and the risk of cancer has been established. In the present study, Star anise (Illicium verum), which is a commonly used condiment in Indian cuisine, was assessed for its anti-carcinogenic potential in N-nitrosodiethylamine (NDEA) initiated and phenobarbital (PB) promoted hepato-carcinogenesis. Rats were randomly selected for eight experimental groups. The carcinogenesis was induced by injecting the rats, with a single dose of NDEA (200mg/kg body weight) intraperitoneally as initiator, followed by promotion with PB (0.05%) in drinking water for 14 consecutive weeks. The treatment with NDEA increased liver weight, while Star anise (Star) treatment reduced the liver weight of rats. The treatment with Star throughout for 20 weeks or during the promotion stage (6-20 weeks) significantly reduced the nodule incidence and nodule multiplicity in the rats, while the treatment with Star at the initiation phase (first 4 weeks) only could not reduce these parameters. The treatment with Star for 20 consecutive weeks significantly reduced the nodule size and nodule volume. The treatment with Star throughout as well as at the promotion stage lowered the lipid peroxidation (LPO) in liver and erythrocytes, while the LPO was not lowered, when Star was administered during initiation stage only. The treatment with Star restored the liver and erythrocyte super-oxide dismutase (SOD) activities to normal in the carcinogenesis-induced rats. The liver catalase (CAT) activity increased in all the treated groups. The erythrocyte CAT activity increased in the rats treated with Star during initiation and promotion stage only. The liver glutathione (GSH) level increased significantly in the groups treated with Star. The erythrocyte GSH level was lowered in the rats treated with NDEA and PB, however, Star treatment helped in increasing the erythrocyte GSH level to some extent. The liver and erythrocyte glutathione-S-transferase (GST) activity increased in all the groups treated with NDEA and PB. The treatment with Star decreased GST level significantly. These results indicate that the treatment with Star reduces the tumor burden, lowers oxidative stress and increases the level of phase II enzymes, which may contribute to its anti-carcinogenic potential.

Free radical scavenging activity, metal chelation and antioxidant power of some of the Indian spices

Food constituents are the major source of various phytochemicals and micronutrients. The importance of these dietary constituents has been stressed in recent years due to their antioxidant and anticarcinogenic potential. Spices used in Indian foods such as cloves (Syzygium aromaticum), licorice (Glycyrrhiza glabra), mace (aril of Myristica fragans), and greater cardamom (Amomum subulatum) were tested for their antioxidant properties in vitro. The metal chelating activity, bleomycin dependent DNA oxidation, diphenyl-p-picryl hydrazyl (DPPH) radical scavenging activity and the ferric reducing /antioxidant power (FRAP) were measured in rat liver homogenate in presence of spices. Metal chelating activity was significantly high with all the spice extracts except mace. The spices due to higher reducing potential (in presence of bleomycin-FeCl_{3}) showed increased DNA oxidation. Cloves showed the highest DPPH radical scavenging activity, followed by licorice, mace and cardamom. FRAP values for cloves were also the highest, while other spices showed comparatively lesser FRAP values. The results show that the spices tested are strong antioxidants and may have beneficial effects on human health.

Modulatory effect of spice extracts on iron-induced lipid peroxidation in rat liver

The antioxidants in foods play an important role in preventing the generation of reactive oxygen species (ROS). Some of the dietary constituents, commonly used in Indian foods such as cloves (Syzygium aromaticum), licorice (Glycyrrhiza glabra), mace (aril of Myristica fragrans) and greater cardamom (Amomum subulatum), were selected as the test samples to find their effect on the inhibition of lipid peroxidation (LPO) in rat liver homogenate. Three different oxidant systems were used to induce LPO. The results show that all the spices have antioxidant activities at various concentrations. None of the spices showed prooxidant properties. The effect of spices on the inhibition of LPO was concentration dependent. Cloves, mace and cardamom inhibited the initiation as well as propagation phases of FeCl_{3} induced LPO, while licorice inhibited the initiation phase only. The reducing power and the superoxide scavenging activity of spices was also measured in vitro. The reducing power of various spices increased with concentration. The percentage inhibition of superoxide radical generation by the spices was also observed to be concentration dependent. The results show that spices used in the present study have significant ability to inhibit LPO due to their polyphenol content, strong reducing power and superoxide radical scavenging activity. Cloves showed the highest antioxidant activity probably due to the higher polyphenol content as compared to other spices.

Prevalence of enterotoxigenic motile aeromonads in children, fish, milk and ice-cream and their public health significance

Motile aeromonads, which have been implicated as causative agents of human gastroenteritis, meningitis. endocarditis and osteomyelitis, were isolated from fish, pasteurized and flavored milk and ice creams. Forty-five isolates of Aeromonas from diarrheic children (100) and 285 food samples comprising of fish (100), milk (85) and ice creams (100) were identified as A. hydrophila (21), A. sobria (16) and A. caviae (8). Five of these 45 isolates of Aeromonoas (3 A. sobria, 2 A. hydrophila) were from fecal samples of diarrheic children under five years of age. Twenty-six of these 45 isolates were found to be enterotoxin producing by ligated rabbit ileum loop technique. Isolation of enterotoxigenic motile aeromonads from food as well as diarrheic children have great public health significance which will be further discussed.

Localization of NORs in spermatogonial metaphase chromosomes of six species of grasshoppers

The silver staining technique was employed to locate Nucleolar Organiser Regions (NORs) in six species of grasshoppers viz. Aiolopus thalassinus F. (Tryxalinae); Oeodaleus abruptus Thunb., Gastrimargus transversus Thunb., Heteropternis respondens Walk. (Oedipodinae); Parahieroglyphus biliniatus Bol. and Spathosternum prasiniferum Walk. (Catantopinae). Usually the NORs were located on the larger elements of the chromosomal complement. However, in O. abruptus NORs were found on autosomes S8 and S9. The salient observations were: (1) NORs were seen in only a few of the several spermatogonial metaphases examined; (2) Active NORs were mostly located either on one chromatid of the homologues or on the homologue depicting heteromorphism; (3) NORs showed either proximal, subproximal or interstitial locations. However, in O. abruptus and P. bilineatus NORs were located at two positions. Distribution of NORs in different species and their probable role in tracing the evolutionary pathways in Acridoidea are discussed.

Testing of Endosulfan and Fenitrothion for genotoxicity in Saccharomyces cerevisiae

Two insecticides, Endosulfan and Fenitrothion, were tested for their ability to induce mitotic crossing-over, mitotic gene conversion and reverse mutation in Saccharomyces cerevisiae. Treatment of cells with Endosulfan increased the frequencies of gene convertants and revertants. However, Fenitrothion treatment did not induce any of these genetic events.