Dextran sodium sulfate alters antioxidant status in the gut affecting the survival of Drosophila melanogaster.

Inflammatory bowel disease (IBD) is a group of disorders characterized by chronic inflammation in the intestine. Several studies confirmed that oxidative stress induced by an enormous amount of reactive free radicals triggers the onset of IBD. Currently, there is an increasing trend in the global incidence of IBD and it is coupled with a lack of adequate long-term therapeutic options. At the same time, progress in research to understand the pathogenesis of IBD has been hampered due to the absence of adequate animal models. Currently, the toxic chemical Dextran Sulfate Sodium (DSS) induced gut inflammation in rodents is widely perceived as a good model of experimental colitis or IBD. Drosophila melanogaster, a genetic animal model, shares ~ 75% sequence similarity to genes causing different diseases in humans and also has conserved digestion and absorption features. Therefore, in the current study, we used Drosophila as a model system to induce and investigate DSS-induced colitis. Anatomical, biochemical, and molecular analyses were performed to measure the levels of inflammation and cellular disturbances in the gastrointestinal (GI) tract of Drosophila. Our study shows that DSS-induced inflammation lowers the levels of antioxidant molecules, affects the life span, reduces physiological activity and induces cellular damage in the GI tract mimicking pathophysiological features of IBD in Drosophila. Such a DSS-induced Drosophila colitis model can be further used for understanding the molecular pathology of IBD and screening novel drugs. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03349-2.

Insight into the evolutionary profile of radio-resistance among insects having intrinsically evolved defence against radiation toxicity.

Ionizing radiation (IR) has wide-ranging applications in various fields. In agriculture, pest control is one of the important applications, because insect pests have become a threat to the global agriculture industry. IR are used routinely to prevent crop loss and to protect stored food commodities. Radio-sterilization and disinfestation treatments are commonly used procedures for insect pest control. From various studies on insect radio-sterilization and disinfestation, it has been established that compared to vertebrates' insects have high levels of radiation resistance. Therefore, to achieve adequate radio-sterilization/disinfestation; exposure to high doses of IR is necessary. However, studies over decades made a presumption that radiation resistance is general among insects. Recent studies have shown that some insect orders are having high IR resistance and some insect orders are sensitive to IR. These studies have clarified that radiation resistance is not uniform throughout insect class. The present review is an attempt to insight at the evolutionary profile of insect species studied for radio-sterilization and disinfestation treatment and are having the trait of radio-resistance. From various studies on insect radiation resistance and after phylogenetic analysis of insect species it appears that the evolutionary near species have drastically different levels of radio-resistance and trait of radiation resistance appears to be independent of insect evolution.

Antennal lobe organisation in ant, Oecophylla smaragdina: A Golgi study.

Antennal lobes (AL) are the primary olfactory centres of the insect brain, the organisation of which reflects the chemosensory repertoire of the insect. The sensory neurons from the antenna, local neurons (LNs), and projection neurons (PNs) constitute the neuropilar organisation of the AL, which often varies according to the ecology and behaviour of the insects. We explored the organisation of the AL in the ant Oecophylla smaragdina through Golgi analysis and other standard histological procedures. Six topographically distinct glomerular clusters were noticed in the AL. AL volume, total number of glomeruli and its spatial organisation were different in the castes of Oecophylla smaragdina. We could count 220 glomeruli in the AL of the major worker, whereas only 140 glomeruli were located in AL of minor workers. LNs with their cell body located on the dorsal, dorso-lateral, ventral, ventro-lateral, and medial position of the AL were characterised. Most of the LNs are oligoglomerular. Uniglomerular and multiglomerular PNs were also identified. The results underline a caste specific organisation of the AL in Oecophylla smaragdina. The characterised LNs and PNs further reveals the complex neural circuitry involved in the processing of important chemical cues related to the lifestyle of the ant.

Radioprotective role of uric acid: evidence from studies in Drosophila and human dermal fibroblast cells.

Exposure to ionizing radiation (IR) is a common phenomenon during medical diagnosis and treatment. IRs are deleterious because cellular exposure to IR can cause a series of molecular events that may lead to oxidative stress and macromolecular damage. Radiation protection is therefore essential and significant for improving safety during these procedures. Over decades several antioxidant molecules have been screened to explore their potential as radio-protectors with little success. Therefore, the current study was carried out to confirm the role of uric acid (UA)-a putative antioxidant molecule in radioprotection using radio-resistant insect Drosophila and human dermal fibroblast (HDF) cells. Here, we demonstrate the depleted levels of UA in the mutant flies of Drosophila melanogaster-rosy and by targeting xanthine oxidase (XO an enzyme involved in UA metabolism), through maintaining flies on an allopurinol mixed diet. Allopurinol is a drug that reduces UA levels by inhibiting XO; it reduces the survival percentage in D. melanogaster compared to wild type flies following gamma irradiation at a dose of 1000 Gy. Enzymatic antioxidants such as superoxide dismutase (SOD), catalase, D. melanogaster glutathione peroxidase (DmGPx) and levels of non-enzymatic antioxidants were measured to evaluate the importance of UA. The results indicate that lack of UA reduces the total antioxidant capacity. The activity of SOD was lowered in male flies. Furthermore, we show that supplementation of UA to HDFs cells in media improved their survival rate following gamma irradiation (2 Gy). From the present study we conclude that UA is a potent antioxidant molecule present in high levels among insects. Also, it appears that UA contributes to the radiation resistance of Drosophila flies. Hence, UA emerges as a promising molecule for mitigating radiation-induced oxidative damage in higher organisms.

Levels and fluxes in enzymatic antioxidants following gamma irradiation are inadequate to confer radiation resistance in Drosophila melanogaster.

Ionizing radiation (IR) causes biological effects either by directly damaging the molecules or by generating free radicals. Antioxidant mechanisms are believed to be involved in neutralising free radicals. Levels of antioxidants therefore assume significance in determining the extent of radiation damage. The fruit fly Drosophila melanogaster (D. melanogaster) exhibits remarkable IR tolerance compared to mammals. Present study addresses the questions (1) Whether levels of antioxidants are high in radio-tolerant fruit fly D. melanogaster compared to mammals? (2) Does the antioxidant activity enhance adequately enough post-irradiation? We analysed enzymatic antioxidant profiles and their fluxes prior to and 60 min post-irradiation (50 Gy). Enzymatic antioxidants were analysed in all the developmental stages of D. melanogaster as the fruit fly shows dramatic changes in radiation resistance during development. Activity of superoxide dismutase (SOD) in Drosophila (pre-irradiation) was comparable to that of mammals. Catalase activity was lower than mammals while glutathione peroxidise (DmGPx) activity was significantly higher. Following irradiation SOD showed changes ranging from 1.40 to 1.62 folds only in larval stages. Catalase activity showed positive change of 1.25 folds only in adults. Activity of DmGPx was largely unaffected. Early pupae showed increased (3.67 fold) glutathione S-transferase activity post-irradiation. Non-enzymatic antioxidants such as total antioxidant capacity showed significant whereas reduced glutathione showed insignificant flux. In conclusion, the levels of enzymatic antioxidants in Drosophila compared to IR sensitive mammals and post-irradiation fluxes in antioxidant enzyme levels appear inadequate to explicate the dramatic radiation resistance observed in Drosophila. The observations are in agreement with the recent findings refuting the role of enzymatic antioxidants in radiation resistance.

Concomitant changes in radiation resistance and trehalose levels during life stages of Drosophila melanogaster suggest radio-protective function of trehalose.

PURPOSE: During development, various life stages of Drosophila melanogaster (D. melanogaster) show different levels of resistance to gamma irradiation, with the early pupal stage being the most radiation sensitive. This provides us an opportunity to explore the biochemical basis of such variations. The present study was carried out to understand the mechanisms underlying radiation resistance during life stages of D. melanogaster. MATERIALS AND METHODS: Homogenates from all the life stages of D. melanogaster were prepared at stipulated age. These homogenates were used for the determination of (1) enzymatic antioxidants: superoxide dismutase (SOD), catalase, D. melanogaster glutathione peroxidase (DmGPx), and glutathione S-transferase (GST); (2) reducing non-enzymatic antioxidants: total antioxidant capacity (TAC), reduced glutathione (GSH) and non-reducing non-enzymatic antioxidant trehalose; and (3) levels of protein carbonyl (PC) content. Age-dependent changes in radiation resistance and associated biochemical changes were also studied in young (2 d) and old (20 and 30 d) flies. RESULTS: TAC and GSH were found high in the early pupal stage, whereas catalase and DmGPx were found to increase in the early pupal stage. The non-feeding third instar (NFTI) larvae were found to have high levels of SOD and GST, besides NFTI larvae showed high levels of trehalose. A remarkable decrease was observed in radiation resistance and trehalose levels during the early pupal stage. The PC level was the highest during early pupal stage and was the lowest in NFTI larvae. Older flies showed high level of PC compared with young flies. CONCLUSION: In vitro increments in trehalose concentration correspond to reduced formation of PCs, suggesting a protective role of trehalose against free radicals. A strong correlation between levels of trehalose and PC formation suggests amelioration of proteome damage due to ionizing radiation (IR). Stages with high trehalose levels showed protected proteome and high radiation resistance, suggesting a significant role for this disaccharide in radiation resistance.

ER stress and genomic instability induced by gamma radiation in mice primary cultured glial cells.

Ionizing radiation induces various pathophysiological conditions by altering central nervous system (CNS) homeostasis, leading to neurodegenerative diseases. However, the potential effect of ionizing radiation response on cellular physiology in glial cells is unclear. In the present study, micronucleus test, comet assay, and RT-PCR were performed to investigate the potential effect of gamma radiation in cultured oligodendrocytes and astrocytes with respect to genomic instability, Endoplasmic Reticulum (ER) stress, and inflammation. Further, we studied the effect of alteration in ER stress specific gene expression in cortex post whole body radiation in mice. Results showed that exposure of gamma radiation of 2Gy in-vitro cultured astrocytes and oligodendrocytes and 7Gy in-vivo induced ER stress and Inflammation along with profuse DNA damage and Chromosomal abnormality. Additionally, we observed downregulation of myelin basic protein levels in cultured oligodendrocytes exposed to radiation. The present data suggests that ER stress and pro inflammatory cytokines serve as the major players in inducing glial cell dysfunction post gamma irradiation along with induction of genomic instability. Taken together, these results indicate that ER stress, DNA damage, and inflammatory pathways may be critical events leading to glial cell dysfunction and subsequent cell death following exposure to ionizing radiation.

Gamma radiation tolerance in different life stages of the fruit fly Drosophila melanogaster.

PURPOSE: Insects are known to have higher levels of radiation tolerance than mammals. The fruit fly Drosophila provides opportunities for genetic analysis of radiation tolerance in insects. A knowledge of stage-specific sensitivity is required to understand the mechanisms and test the existing hypothesis of insect radiation tolerance. MATERIALS AND METHODS: Drosophila melanogaster were irradiated using gamma rays at different life stages. Irradiation doses were chosen to start from 100-2200 Gy with increments of 100 Gy, with a dose rate of 12.5 and 25 Gy/min. The threshold of mortality, LD50 and LD100 1 h post-irradiation was recorded for larvae and adults and 24 h post-irradiation for eggs and after 2-3 days for early and late pupae. Total antioxidant capacity for all the life stages was measured using the phosphomolybdenum method. RESULTS: Twenty-four hours post-irradiation, 100% mortality was recorded for eggs at 1000 Gy. One hour post irradiation 100% mortality was recorded at 1300 Gy for first instar larvae, 1700 Gy for second instar larvae, 1900 Gy for feeding third instar larvae and 2200 Gy for non-feeding third instar larvae. Post-irradiation complete failure of emergence (100% mortality) was observed at 130 Gy for early pupae and 1500 Gy for late pupae; 100% mortality was observed at 1500 Gy for adults. The values of LD50 were recorded as 452 Gy for eggs, 1049 Gy for first instar larvae, 1350 Gy for second instar larvae, 1265 Gy for feeding third instar larvae, 1590 Gy for non-feeding third instar larvae, 50 Gy for early pupae, 969 Gy for late pupae, 1228 Gy for adult males and 1250 Gy for adult females. CONCLUSIONS: Early pupae were found to be prone to radiation, whereas the non-feeding third instar larvae were most resistant among all stages. The chromosome number being constant and total antioxidant capacity being nearly constant in all stages, we suggest that high rate of cell division during early pupae makes this stage sensitive to radiation.

A review on detection methods used for foodborne pathogens.

Foodborne pathogens have been a cause of a large number of diseases worldwide and more so in developing countries. This has a major economic impact. It is important to contain them, and to do so, early detection is very crucial. Detection and diagnostics relied on culture-based methods to begin with and have developed in the recent past parallel to the developments towards immunological methods such as enzyme-linked immunosorbent assays (ELISA) and molecular biology-based methods such as polymerase chain reaction (PCR). The aim has always been to find a rapid, sensitive, specific and cost-effective method. Ranging from culturing of microbes to the futuristic biosensor technology, the methods have had this common goal. This review summarizes the recent trends and brings together methods that have been developed over the years.

Brain aging, memory impairment and oxidative stress: a study in Drosophila melanogaster.

Memory impairment during aging is believed to be a consequence of decline in neuronal function and increase in neurodegeneration. Accumulation of oxidative damage and reduction of antioxidant defense system play a key role in organismal aging and functional senescence. In our study, we examined the age-related memory impairment (AMI) in relation to oxidative stress using Drosophila model. We observed a decline in cognitive function in old flies with respect to both short-lived and consolidated forms of olfactory memory. Light and electron microscopy of mushroom bodies revealed a reduction in the number of synapses and discernible architectural defects in mitochondria. An increase in neuronal apoptosis in Kenyon cells was also evident in aged flies. Biochemical investigations revealed a comparable age-associated decrease in the activity of antioxidant enzymes such as catalase and superoxide dismutase as well as the GSH level, accompanied by an increase in the level of lipid peroxidation and generation of reactive oxygen species in the brain. There was no significant difference in the activity level of AChE and BChE enzymes between different age groups while immunohistochemical studies showed a significant decrease in the level of ChAT in 50-day-old flies. RNAi-mediated silencing of cat and sod1 genes caused severe memory impairment in 15-day-old flies, whereas, over-expression of cat gene could partially rescue the memory loss in the old flies. We demonstrated that a Drosophila long-lived strain, possessing enhanced activity of antioxidant enzymes and higher rate of resistance to oxidative stress, shows lower extent of AMI compared to normal lifespan strain. Present study provides evidence for involvement of oxidative stress in AMI in Drosophila.

Minimal access surgery in newborns and small infants; five years experience.

AIMS AND OBJECTIVES: The aim of this study was to assess and present the outcome (initial experience and lessons learnt) of minimally invasive surgery for various indications in neonates and small infants (< 5 kg) at a single medical centre. MATERIALS AND METHODS: A retrospective analysis was performed on 65 patients (age day 2 to 10 months) managed with minimal access surgery (MAS) for various indications, between 2005 and 2010. We analyzed demographic information, procedures, complications, outcomes, and follow-up and overall feasibility of the procedure. RESULTS: No serious complications except one death in congenital diaphragmatic hernia (CDH) (due to other comorbidities) occurred. Intra operative hypercarbia and hypoxia were observed more frequently in thoracoscopic procedures. Intra operative hypothermia was not common and was well tolerated. Conversion to open procedure (n = 5), post operative ileus (n = 3), port site infection (n = 5) were other complications. CONCLUSION: MAS in neonates and small infants is a technically demanding but a feasible choice available. Some prior experience in older children is required for safe and effective outcome. Good quality optics, video equipments and instruments are required for safe and effective procedure. Intra operative measurement of oxygen saturation and temperature, and diligent post operative ICU care are mandatory for safe and successful outcome.

Role of hyperbaric oxygen therapy in severe head injury in children.

AIM: A brain injury results in a temporary or permanent impairment of cognitive, emotional, and/or physical function. Predicting the outcome of pediatric brain injury is difficult. Prognostic instruments are not precise enough to reliably predict individual patient's mortality and long-term functional status. The purpose of this article is to provide a guide to the strengths and limitations of the use of hyperbaric oxygen therapy (HBOT) in treating pediatric patients with severe brain injury. MATERIALS AND METHODS: We studied total 56 patients of head injury. Out of them 28 received HBOT. Only cases with severe head injury [Glasgow Coma Scale (GCS) < 8] with no other associated injury were included in the study group. After an initial period of resuscitation and conservative management (10-12 days), all were subjected to three sessions of HBOT at 1-week interval. This study group was compared with a control group of similar severity of head injury (GCS < 8). RESULTS: The study and control groups were compared in terms of duration of hospitalization, GCS, disability reduction,and social behavior. Patients who received HBOT were significantly better than the control group on all the parameters with decreased hospital stay, better GCS, and drastic reduction in disability. CONCLUSION: In children with traumatic brain injury, the addition of HBOT significantly improved outcome and quality of life and reduced the risk of complications.

Comparative study on foraminifera of east and west coast of India.

The oceanographic conditions of west and east coasts of India provide variations in ecological conditions. Hence, the present study was undertaken to assess the geographic distribution and diversity of foraminifera (Protista) of west and east Coasts of India to gain insights in to ecological conditions that effect their distribution. The intertidal sediment samples, collected for a period of two years from October 2004 to September 2006 were analysed for foraminiferal diversity and sediment characteristics by standard methods. Relatively high densities (west coast--156 to 19,400 g(-1), east coast--37-214 g(-1)) and diversities were observed at all the sites of the West (74 species) compared to the east coast (57 species). Thirty three species were common to both the coasts. Forty one and 24 species were found to be unique to west and east coast, respectively. Foraminifera of west and east coasts form distinct clusters as revealed by Bray-Curtis cluster analysis, indicating distinctly different foraminiferal assemblages. The geographical and oceanographic conditions thus seem to influence a differential diversity of forams.

Laparoscopic repair of pediatric inguinal hernia--is vascularity of the testis at risk? A study of 125 testes.

AIM: The aim of this study was to study the effects of laparoscopic inguinal hernia repair on testicular perfusion and size. MATERIALS AND METHODS: A prospective study concerning laparoscopic inguinal hernia repair was performed for an 18-month period to evaluate testicular perfusion and size in the preoperative, early postoperative (within 48 hours of surgery), and late postoperative periods (6 months after surgery) using Doppler ultrasound (DUS) (both duplex and power Doppler mode). Laparoscopic closure of the deep inguinal ring was accomplished with a purse string suture (Nylon 3-0) using standard 3-port technique. The testis units were divided in 2 groups: group 1 comprising testis units in which a resistive index (RI) could be calculated and group 2 with instances in which an RI could not be calculated but showed blood flow consistently on DUS. RESULTS: A total of 112 boys underwent laparoscopic inguinal hernia repair with 100 available for complete follow-up and data analysis. One hundred twenty-five inguinal (25 bilateral) hernia repairs were performed. Group 1 had 80 testis units. There was no significant difference in values of RI between preoperative, early postoperative, and late postoperative periods. Group 2 had 45 testis units. Resistive index could not be calculated. Seventy-five percent showed only systolic blood flow on spectral analysis; hence, RI, 1; and the rest showed the presence of blood flow on power Doppler scan. All testis units consistently showed blood flow in the early and late postoperative period. No testicular atrophy was found at 6-month follow-up examination on DUS. CONCLUSION: Laparoscopic repair of inguinal hernia in children does not affect testicular perfusion or growth.

Early experience with thoracoscopic repair of congenital diaphragmatic hernias in pediatric age group: results and lessons learned.

PURPOSE: To describe the surgical technique, initial results, and overview indications of thoracoscopic repair of congenital diaphragmatic hernia. PATIENTS AND METHODS: A retrospective review was undertaken of patients with CDH who underwent thoracoscopic repair from January 2006 to July 2010, in department of pediatric surgery in a tertiary care institute in India. Patients underwent surgery under general anesthesia. Reduction of the hernia contents was carried out using one trocar for telescope and two operating trocars. Pleural insufflation with carbon dioxide was maintained at a pressure of 6-10 mmHg. The hernia defect was repaired using nonabsorbable interrupted sutures. RESULTS: There were 17 patients, including 12 boys and 5 girls. Among 12 infants, there were 6 patients younger than 30 days. The other 5 patients were older than 1 year. The hernia was located in the left side in 14 patients and in the right side in 3 patients. The mean operative time was 110 min. Conversion was required in three patients. There were one recurrence and one postoperative death. CONCLUSIONS: Thoracoscopic repair is feasible and safe for children with CDH, including selective newborn. The technique causes minimal trauma, results in good respiratory function, and promotes early recovery.

Ruptured rectal duplication cyst with classical bladder exstrophy.

A newborn boy was brought to us, 2 hours after birth, with a mucosal-lined left hemiperineal lesion associated with classical bladder exstrophy and an anterolaterally displaced anus. Perineal anatomy was restored by excising the mucosa lined lesion. The bladder closure for classical bladder exstrophy was done at the same time. Histologically, gastric, respiratory, and small intestinal epithelia were present in the mucosa. A rectal duplication cyst that had ruptured in utero through the hemiperineum could explain the anomaly. The association of classical bladder exstrophy with ruptured rectal duplication cyst has never previously been described in the literature.

Results of anterior chamber clearance via the pars plana in pseudophakic endophthalmitis.

PURPOSE: Patients with endophthalmitis have extensive fibrinous exudates in the anterior chamber. Clearance of these exudates in pseudophakic patients during vitrectomy is difficult. We evaluated the results of the pars plana approach for clearing these exudates. MATERIAL AND METHODS: Eighteen patients with pseudophakic endophthalmitis underwent clearance of anterior chamber exudates through the pars plana approach after initial creation of a peripheral iridectomy with a vitrectome. RESULTS: The exudates were adequately cleared in all 18 patients with good posterior segment visualization during vitrectomy. Minor punctate iris bleeds (4 patients), intraoperative dislocation of the intraocular lens (IOL) (1 patient) and postoperative dislocation of the IOL following blunt trauma, 9 months after vitrectomy (1 patient) were the complications noted. CONCLUSION: This technique is simple, safe and helps clearing anterior chamber exudates. It also permits excellent visualization during vitrectomy for pseudophakic endophthalmitis.