32 research outputs found
Doxorubicin induced histomorphometric changes in testes of albino rat
Anticancer drugs like doxorubicin have been found to affect male gonads thereby leading to infertility. This study was conducted to evaluate the effects of doxorubicin over short, mid and long term on testes of male albino rats. Sixty male albino rats aged 6-8 weeks were taken for study. The rats were randomly divided into 3 groups of experimental (each group containing 10 rats) and 3 groups of control (each group containing 10 rats). The experimental groups were given a single dose of doxorubicin i.e. 10 mg/kg body weight intra-peritoneally and sacrificed after 3 different duration for each group (second week, eighth week and sixteenth week). All rats under 3 control groups were given a single intra-peritoneal dose of 2.5 ml/kg body weight normal saline and sacrificed with their respective experimental groups. Significant difference in diameters (p=0.029) and cross-sectional area (p=0.028) of seminiferous tubules was observed between short term experimental and short term control rats. For both between midterm experimental and midterm control group, and between long term experimental and long term control group, a significant difference in right testis weight (p<0.001 for both), left testis weight (p<0.001 for both), volume of testis (p<0.001 and p=0.038), diameter (p<0.001 for both) and area (p<0.001 for both) of seminiferous tubules was observed. As compared to short term experimental group, midterm experimental group and long term experimental group had significantly lower right testis weight (p<0.001 for both), left testis weight (p<0.001 for both), diameter of seminiferous tubule (p<0.001 for both) and cross-sectional area of seminiferous tubule (p<0.001 both). Cross-sections of the seminiferous tubules of all the control groups had normal architecture. However, there was progressive destruction of seminiferous tubules structure across the experimental groups. Doxorubicin has deleterious effect on seminiferous tubules of albino rat testis.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 10-1
Alterations in the leaf lipidome of \u3ci\u3eBrassica carinata\u3c/i\u3e under high-temperature stress
Background: Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/ 15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry.
Results: Temperature treatment significantly affected the growth and development of Avanza 641. Both hightemperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18: 3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts.
Conclusions: The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties
Thyroid Dysfunction and Associated Risk Factors among Nepalese Diabetes Mellitus Patients
Objectives. To assess thyroid function and associated risk factors in Nepalese diabetes mellitus patients. Methods. A cross-sectional study was carried out among 419 diabetes mellitus patients at B. P. Koirala Institute of Health Sciences, Dharan, Nepal. Information on demographic and anthropometric variables and risk factors for thyroid dysfunction was collected. Blood samples were analysed to measure thyroid hormones, blood sugar, and lipid profile. Results. Prevalence rate of thyroid dysfunction was 36.03%, with subclinical hypothyroidism (26.5%) as the most common thyroid dysfunction. Thyroid dysfunction was much common in females (42.85%) compared to males (30.04%) p=0.008 and in type 1 diabetes (50%) compared to type 2 diabetes mellitus (35.41%) p=0.218. Diabetic patients with thyroid dysfunction had higher total cholesterol, HDL cholesterol, and LDL cholesterol in comparison to patients without thyroid dysfunction. Significant risk factors for thyroid dysfunction, specifically hypothyroidism (overt and subclinical), were smoking (relative risk of 2.56 with 95% CI (1.99–3.29, p<0.001)), family history of thyroid disease (relative risk of 2.57 with 95% CI (2.0–3.31, p<0.001)), and female gender (relative risk of 1.44 with 95% CI (1.09–1.91, p=0.01)). Conclusions. Thyroid dysfunction is common among Nepalese diabetic patients. Smoking, family history of thyroid disease, and female gender are significantly associated with thyroid dysfunction
Incidental Intraoperative Diagnosis of Term Conjoined Twins: A Case Series
Conjoined twins (Siamese twins) represent the rarest form of twin pregnancy. Reported here are two rare cases of conjoined term twins presented to the department of Obstetrics and Gynaecology within 3 months. The first case, 32 years of gravida 6 parity 5 referred from periphery after full trial of labour following multi-organ dysfunction and term intrauterine dead twins. Intraoperatively it was dead conjoined thoraco-omphalopagus females. The patient died after 3 days following multiorgan dysfunction syndrome and disseminated intravascular coagulation. The second case, 22 years gravida 2 parity 1 also referred from periphery in second stage of labour with diagnosis of 39 weeks intrauterine dead twins with obstructed labour, delivered by caesarean with intraoperative conjoined dead females of thoracophagus type. Twins are high-risk pregnancy. This rare diagnosis with complications could have been prevented by regular antenatal checkups, ultrasonography performed by radiologists and early referral antenatally in labour along with multidisciplinary approach
Vision, challenges and opportunities for a Plant Cell Atlas
With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, resulting in a roadmap that acknowledges the current knowledge gaps and technical challenges, and underscores how the PCA initiative can help to overcome them.</jats:p
Behavioral and neurobiological changes in mice deficient in synaptic cell adhesion molecules NEGR1 and NCAM2
Interactions between neurons are mediated by cell adhesion molecules (CAMs). NCAM2 and NEGR1 are two CAMs, which accumulate in synapses. Abnormal expression of these synaptic CAMs is associated with behavioral abnormalities and neurodevelopmental disorders in humans. The effects caused by deficiency in these CAMs in the brain remain, however, unclear. To better understand human conditions associated with the loss of NCAM2 and NEGR1, in this thesis, we analyzed the behavior of NCAM2 and NEGR1 deficient mice and performed immunohistochemical analyses of the brain to study the underlying mechanisms of these effects.
We found that NCAM2 deficiency in mice leads to the impairment in short-term memory, mild cognitive deficit, and causes an increase in olfactory acuity and repetitive and self-grooming behaviors. Our immunohistochemical studies showed shortening of the infrapyramidal bundle of the mossy fibers in the hippocampus of the NCAM2 knockout mice suggesting axonal guidance defects. Similar axon guidance defects and changes in behavior were also observed in mice deficient in BACE1, an enzyme involved in processing of NCAM2. Further analysis showed changes in distribution and a reduction in levels of BACE1 protein in the hippocampus in NCAM2 knockout mice. Additionally, cell culture studies showed that NCAM2 knockout neurons were characterized by altered organization of the Golgi body organelles and lower levels of the microtubule-associated proteins tau and CRMP2, which are required for transporting protein cargoes and maintaining the cytoskeleton.
We observed spatial and short-term memory impairment, hyposmia, and a reduction in motivation towards highly palatable food rewards in NEGR1 knockout mice. These mice had lower densities of synapses in the hippocampus, particularly of those formed by mossy fibers. The overall size of the suprapyramidal bundle of mossy fibers was reduced in NEGR1 knockout mice. These effects were accompanied by the deposition of alpha-synuclein aggregates in the hippocampus. Similarly, the density of inhibitory synapses was reduced in the CA3 pyramidal cell layer of the hippocampus and arcuate nucleus of hypothalamus, which is involved in regulating the feeding behavior.
In conclusion, we found that NCAM2 and NEGR1 deficiency causes synaptic changes in the brain, which are accompanied by abnormalities in learning, suggesting that both proteins are involved in regulating neuronal development and plasticity. Our data indicate that NCAM2 and NEGR1 deficiency can directly contribute to neurodevelopmental and other types of disorders in people with variations in the genes coding for NCAM2 and NEGR1
Functional Role of Protein Kinases and Phosphatase in Abiotic Stress Response in Plants
Soybean (Glycine max) and rice (Oryza sativa) are the most important crops cultivated worldwide. The productivity of both crops is severely limited due to drought stresses. Abscisic acid (ABA) signaling is one of the crucial phytohormones which acts as the signaling mediator in different environmental stress for adaptive response of plants. In this study, functional characterization of abscisic acid-activated protein kinase-like kinase 1 (AALK1), and low molecular weight protein tyrosine phosphatase (LMWPTP) were studied by developing gain-ofunction and loss-ofunction phenotypes by transgenesis. Physiological response of AALK1 showed that AALK1 modulates the drought stress response ins soybean plants. The study has demonstrated several key genes are differentially expressed control, and aalk1-RNAi silenced lines under drought treatment. The AALK1 overexpression lines enhanced the transcription of other ABA-responsive genes, indicating that the AALK1 is a positive regulator of ABA-mediated stress signaling pathways in soybean. The phylogenetic analysis and domain analysis also supports that AALK1 is abscisic acid-activated protein kinase and has a role in drought response. Phenotype analysis of LMWPTP in rice showed that transgenic overexpression of LMW-PTP exhibited significantly improved drought tolerance in comparison to RNAi silencing and control plants ,which indicates that LMWPTP modulates the drought stress tolerance of rice plants. Further, 5 putative tyrosine phosphorylated proteins were detected through immunoblotting and identified by mass spectrometry. Some of these tyrosine phosphorylated proteins are likely to be target proteins of LMWPTP. Together, the present findings strengthen the knowledge about the functional role of AALK1 and LMWPTP, which can be utilized as a promising gene-based molecular marker in transgenic breeding for generating crop plants with improved drought tolerance which ultimately improve the grain yields
Silicon Enhances Plant Vegetative Growth and Soil Water Retention of Soybean (Glycine max) Plants under Water-Limiting Conditions
Silicon has been implicated as a factor affecting the degree of resistance to abiotic stresses in several plant species. However, the role of silicon in soybean (Glycine max) under water-limiting conditions is not yet fully understood. This study was conducted to evaluate the effects of silicon application on the vegetative growth of two soybean cultivars (Asgrow 5332 and Progeny 5333) grown under water-limiting conditions. Silicon was provided by adding silicate to the soil. Water-limiting treatments were imposed on plants at two vegetative growth stages for 20 days by irrigating with a reduced amount of water (66% or 33% of the required water). Silicate application enhanced plant height, leaf area, and total dry weight of soybean plants. Significant increases in root volumes were observed in both the silicate-treated cultivars compared to the control plants under water-limiting conditions (33% irrigation). Net photosynthesis and stomatal conductance were decreased, but the quantum efficiency of photosystem II (Fv’/Fm’) did not change under the same irrigation condition, which indicates photosynthesis downregulation through stomatal limitation. Silicate-treated plants in both cultivars had higher water use efficiency as compared to control plants under water-limiting conditions (irrigated with 66% or 33% of required water). Under water-limiting conditions, the soil moisture content was significantly higher in pots containing silicate than in those without added silicate, suggesting that silicon application improves water holding capacity. Taken together, the results from this study indicate that silicon application can improve the vegetative growth of soybeans under low water conditions by increasing the water use efficiency of plants and enhancing the soil’s ability to retain moisture
Abscisic acid and abiotic stress tolerance in crop plants
Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, ABA (abscisic acid) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression
Phytohormones and their metabolic engineering for abiotic stress tolerance in crop plants
Abiotic stresses including drought, salinity, heat, cold, flooding, and ultraviolet radiation causes crop losses worldwide. In recent times, preventing these crop losses and producing more food and feed to meet the demands of ever-increasing human populations have gained unprecedented importance. However, the proportion of agricultural lands facing multiple abiotic stresses is expected only to rise under a changing global climate fueled by anthropogenic activities. Identifying the mechanisms developed and deployed by plants to counteract abiotic stresses and maintain their growth and survival under harsh conditions thus holds great significance. Recent investigations have shown that phytohormones, including the classical auxins, cytokinins, ethylene, and gibberellins, and newer members including brassinosteroids, jasmonates, and strigolactones may prove to be important metabolic engineering targets for producing abiotic stress-tolerant crop plants. In this review, we summarize and critically assess the roles that phytohormones play in plant growth and development and abiotic stress tolerance, besides their engineering for conferring abiotic stress tolerance in transgenic crops. We also describe recent successes in identifying the roles of phytohormones under stressful conditions. We conclude by describing the recent progress and future prospects including limitations and challenges of phytohormone engineering for inducing abiotic stress tolerance in crop plants