Anticonvulsant Effects of Carbonic Anhydrase Inhibitors: The Enigmatic Link Between Carbonic Anhydrases and Electrical Activity of the Brain

Neurochemical Research - Acetazolamide (ACZ), a sulfonamide carbonic anhydrase (CA) inhibitor, was first introduced into medical use as a diuretic in the1950s. Shortly after its introduction, its...     

Effect of patulin on the interdigitating dendritic cells (IDCs) of rat thymus

Patulin is a common fungal contaminant of ripe apples used for the production of apple juice concentrates and it is also present in other fruits, vegetables and food products. Patulin is a secondary metabolite produced by species of the genera Penicillium, Aspergillus and Byssochlamys. Patulin has been reported to be mutagenic, carcinogenic and teratogenic. Antigen-presenting cells (APCs) are of prime importance in the innate immune response; they capture antigen in tissues and then migrate to the lymphoid organs to present the antigen to T lymphocytes. Thus, they are crucial for the initiation of immunity. Interdigitating dendritic cells (IDCs) are a subset of APCs that are present at the lymphatic organs. In the thymus, they act in positive and negative selection during T cell development. In the present study, patulin was administered orally to growing male rats aged 5-6 weeks. A dose of 0.1 mg kg(-1) bw day(-1) was given to rats for a period of 60 or 90 days daily. The effect of patulin on the IDCs of thymus was investigated by transmission electron microscopy (TEM), and the results were evaluated in terms of cell destruction. In the rats of the control group, it was observed that the IDCs had an indented nucleus, a clear cytoplasm and numerous membrane extensions. In the cytoplasm, a well-developed golgi complex, mitochondria, granular endoplasmic reticulum and a small number of lysosomal structures were observed. At day 60 of patulin-treated rat groups (P-60), loss of cristae in mitochondria and chromatin margination and lysis in the nucleus were found. It was observed that the IDCs had a perinuclear area of cytoplasm surrounded by a peripheral electron-lucent zone. In the cytoplasm of the 90-day patulin-treated rat group (P-90), a peripheral electron-lucent zone was also found, similar to the P-60 group. Additionally increase in vesicular and lysosomal structures, increase in apoptotic bodies and condensation of chromatin in the nucleus were noted. It was observed that patulin leads to apoptotic body formation and cell apoptosis in the IDCs of rat thymus especially in the P-90-treated groups.     

Estimating reaction norms for predictive population parameters,age specific mortality,and mean longevity in temperature‐dependent cohorts of Culex quinquefasciatus Say (Diptera: Culicidae)

Culex quinquefasciatus plays a major role in the transmission of important parasites and viruses throughout the world. Because temperature is an important limiting factor on growth and longevity of all mosquito species, estimating the reaction norms provides very important basic information for understanding both plasticity and individual variations of the population. In the present study, Cx. quinquefasciatus were maintained at five different constant temperatures (15°, 20°, 23°, 27°, and 30°C) for two subsequent generations. Reproductive population parameters in blood‐fed mated females and longevities of virgin and blood‐fed mated adults reared at different temperatures were compared for the two generations. Longevity increased as temperature decreased within a range of 15° to 30°C for the unmated adults, and 15° to 27°C for the mated and blood‐fed adults. Generation times were as long as 124.07 and 106.76 days for two subsequent generations reared at 15°C, and the highest intrinsic rate of increase (r_m) values were estimated at 0.22 and 0.18, respectively, from the cohorts reared at 27°C. For survival rates, reproductive rates (R₀), and r_m values, 30°C was found to be a critical temperature for this species. These cohorts produced the smallest amount of eggs (R₀= 5.06), r_m values decreasing across generations (from 0.11 to 0.06), and the survival rates from egg to adult were found to be insufficient (16.1 and 10.8%). Additionally, the rate of exponential increase with age and age specific mortalities (b) were calculated for the virgin cohorts. Age specific mortality rates increased as temperature decreased. The increase in mortality rates started to accelerate at 27°C and was more pronounced at 30°C, for both females and males. We estimated the coefficients of variation for the b values in which females have smaller coefficients than those of the males at all temperatures.     

A Pseudomonas aeruginosa TIR effector mediates immune evasion by targeting UBAP1 and TLR adaptors

Bacterial pathogens often subvert the innate immune system to establish a successful infection. The direct inhibition of downstream components of innate immune pathways is particularly well documented but how bacteria interfere with receptor proximal events is far less well understood. Here, we describe a Toll/interleukin 1 receptor (TIR) domain‐containing protein (PumA) of the multi‐drug resistant Pseudomonas aeruginosa PA7 strain. We found that PumA is essential for virulence and inhibits NF‐κB, a property transferable to non‐PumA strain PA14, suggesting no additional factors are needed for PumA function. The TIR domain is able to interact with the Toll‐like receptor (TLR) adaptors TIRAP and MyD88, as well as the ubiquitin‐associated protein 1 (UBAP1), a component of the endosomal‐sorting complex required for transport I (ESCRT‐I). These interactions are not spatially exclusive as we show UBAP1 can associate with MyD88, enhancing its plasma membrane localization. Combined targeting of UBAP1 and TLR adaptors by PumA impedes both cytokine and TLR receptor signalling, highlighting a novel strategy for innate immune evasion.     

Influence of vanadium supplementation on oxidative stress factors in the muscle of STZ-diabetic rats

In recent years, the role of free radical damage consequent to oxidative stress is widely discussed in diabetic complications. In this aspect, the protection of cell integrity by trace elements is a topic to be investigated. Vanadium is a trace element believed to be important for normal cell function and development. The aim of the present study was to investigate the effect of vanadyl sulfate supplementation on the antioxidant system in the muscle tissue of diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) to male Swiss albino rats. The rats were randomly divided into 4 groups: Group I, control; Group II, vanadyl sulfate control; Group III, STZ-diabetic untreated; Group IV, STZ-diabetic treated with vanadyl sulfate. Vanadyl sulfate (100 mg/kg) was given daily by gavage for 60 days. At the last day of the experiment, rats were killed, muscle tissues were taken, homogenized in cold saline to make a 10% (w/v) homogenate. Body weights and blood glucose levels were estimated at 0, 30 and 60th days. Antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), as well as carbonic anhydrase (CA), myeloperoxidase (MPO) activities and protein carbonyl content (PCC) were determined in muscle tissue. Vanadyl sulfate administration improved the loss in body weight due to STZ-induced diabetes and decreased the rise in blood glucose levels. It was shown that vanadium supplementation to diabetic rats significantly decrease serum antioxidant enzyme levels, which were significantly raised by diabetes in muscle tissue showing that this trace element could be used as preventive for diabetic complications.     

The protective effect of L-carnitine against hippocampal damage due to experimental formaldehyde intoxication in rats

We investigated the protective effects of L-carnitine on hippocampus tissue damage in rats during experimental formaldehyde (FA) intoxication. Male Wistar albino rats were assigned into four groups: (1) control (C), (??2) formaldehyde (FA), (3) formaldehyde + 0.5 g/kg of L-carnitine (FA + 0.5 LC) (4) formaldehyde + 1 g/kg L-carnitine (FA + 1 LC). At the end of the 14 day trial period, animals were sacrificed by decapitation under anesthesia. The hippocampus tissue samples were extracted to measure MDA, GSH and SOD activity. Neuronal degeneration was assessed based on histopathological (hematoxylin and eosin) and immunohistochemical (anti-ubiquitin) examination. To detect oxidative stress, specimens were reacted with anti-Cu/Zn-SOD antibody. After administering L-carnitine with FA to the animals, the activities of SOD and GSH increased, but the levels of MDA decreased in hippocampus tissue. Neuronal degeneration was observed in the FA group. L-carnitine administration reduced neuronal degeneration and histological structure was similar to controls. After FA application, degenerated hippocampus neurons were stained with anti-ubiquitin and Cu/Zn-SOD antibodies; weakly positive staining was observed in L- carnitine-treated groups. L-carnitine may be useful for preventing oxidative damage in the hippocampus tissue due to formaldehyde intoxication.     

Inflammatory thresholds and the species-specific effects of colonising bacteria in stable chronic obstructive pulmonary disease

Background

There has been increasing interest in the use of newer, culture-independent techniques to study the airway microbiome of COPD patients. We investigated the relationships between the three common potentially pathogenic microorganisms (PPMs) Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, as detected by quantitative PCR (qPCR), and inflammation and health status in stable patients in the London COPD cohort.

Methods

We prospectively collected sputum, serum and plasma samples for analysis of airway bacterial presence and load, and airway and systemic inflammation from 99 stable COPD patients between January 2011 and October 2012. Health status was measured with St George’s Respiratory Questionnaire and COPD Assessment Test.

Results

Airway inflammation and plasma fibrinogen, but not C-reactive protein, were greater in samples with PPM detection (p < 0.001, p = 0.049 and p = 0.261, respectively). Increasing total bacterial load was associated with increasing airway (p < 0.01) but not systemic inflammation (p > 0.05). Samples with high total bacterial loads had significantly higher airway inflammation than both samples without PPM detection and those with lower loads. Haemophilus influenzae presence was associated with significantly higher levels of airway but not systemic inflammation for all given pathogen loads (p < 0.05), and was significantly greater than with other PPMs. No association was observed between inflammation and health status (p > 0.05).

Conclusions

Airway and systemic inflammation, as measured by fibrinogen, is greater in stable COPD patients with PPMs detected using the culture-independent qPCR technique. The airway, but not systemic inflammatory response, appears to have a total pathogen-load threshold and appears attributable to Haemophilus influenzae. However, discordance between inflammation and health status was observed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0114-1) contains supplementary material, which is available to authorized users.     

Narrow-sense heritability of body size and its response to different developmental temperatures in Culex quinquefasciatus (Say 1923)

Body size is an important trait involved in overall fitness through its effects on mating success, fecundity, resource acquisition and mortality, and desiccation resistance. In this study, we raised inbred Culex quinquefasciatus mosquito cohorts at different developmental temperatures of 20°, 23°, and 27° C. As an indicator of the amount of genetic variation in body size, we estimated the narrow-sense heritability of body sizes defined as wing aspect ratios. Our results show that narrow-sense heritability of the body size increased as the developmental temperature increased. We also detected the presence of strong genotype-by-environment (G × E) interaction from low cross-environmental correlations. The body size of each temperature regime followed the general rule that higher temperatures produce smaller individuals. We suggest that the increase in genetic variation with increasing temperature might be due to an unleashing of the cryptic genetic variation of the putative genes affecting body size. We conclude that this increase in genetic variation tracking the environmental (developmental temperature) change could have considerable implications for the distribution and range expansion of Cx. quinquefasciatus, especially in warmer environments.     

Dietary use and conservation concern of edible wetland plants at indo-burma hotspot: a case study from northeast India

Background

The wetlands of the North East India fall among the global hotspots of biodiversity. However, they have received very little attention with relation to their intrinsic values to human kind; therefore their conservation is hardly addressed. These wetlands are critical for the sustenance of the tribal communities.

Methods

Field research was conducted during 2003 to 2006 in seven major wetlands of four districts of Manipur state, Northeast India (viz. Imphal-East, Imphal-West, Thoubal, and Bishnupur). A total of 224 wetland-plant-collectors were interviewed for the use and economics of species using semi-structured questionnaires and interview schedules. Imphal, Bishenpur and Thoubal markets were investigated in detail for influx and consumption pattern of these plants. The collectors were also inquired for medicinal use of wetland species. Nutritive values of 21 species were analyzed in laboratory. The vouchers were collected for all the species and deposited in the CSIR-NEIST (Formerly Regional Research Laboratory), Substation, Lamphelpat, Imphal, Manipur, India.

Results

We recorded 51 edible wetland species used by indigenous people for food and medicinal purposes. Thirty eight species had high medicinal values and used in the traditional system to treat over 22 diseases. At least 27 species were traded in three markets studied (i.e. Imphal, Thoubal and Bishenpur), involving an annual turnover of 113 tons of wetland edible plants and a gross revenue of Rs. 907, 770/- (US$1 = Rs. 45/-). The Imphal market alone supplies 60% of the total business. Eighty per cent of the above mentioned species are very often used by the community. The community has a general opinion that the availability of 45% species has depleted in recent times, 15 species need consideration for conservation while another 7 species deserved immediate protection measures. The nutrient analysis showed that these species contribute to the dietary balance of tribal communities.

Conclusions

Considering the importance of wild wetland plants in local sustenance, it is suggested to protect their habitats, develop domestication protocols of selected species, and build programs for the long-term management of wetland areas by involving local people. Some medicinal plants may also be used to develop into modern medicines.

     

Formulation of a microparticle carrier for oral polyplex-based DNA vaccines

Oral induction of a disseminated mucosal immune response with polyplex-based DNA vaccines requires the delivery of intact polyplexes (polyelectrolyte complexes formed by self-assembly of plasmid DNA with a cationic polymer) to subepithelial lymphoid tissue (e.g. Peyer's patches) within the gastrointestinal tract. This work describes the formulation of a microparticle polyplex carrier allowing the potential of this approach to be realised. PEGylated PEI/DNA polyplexes (DNA concentration 20 microg/ml) formed at N/P 5:0 (defined as the ratio of polycation amino groups to DNA phosphates) were stable to salt-induced aggregation and could be concentrated to a final DNA concentration of 1 mg/ml without polyplex size increase. Polyplexes containing 1:1 polyethylene glycol (PEG)/polyethylenimine (PEI) ratio (mass/mass) gave similar levels of luciferase gene expression in B16F10 cells compared to non-PEG complexes. Poly-(D,L-lactide-co-glycolide) (PLGA) microparticles containing PEGylated polyplexes (approximately 17% DNA encapsulation efficiency) were formulated using a modified double emulsion solvent evaporation method. The microencapsulation and release of intact polyplexes from the microparticle carrier was demonstrated using polyanion (heparin sulfate and poly(aspartic acid) (PAA)) displacement techniques and electron microscopy. Microparticles containing PEGylated polyplexes (24 microg beta-galactosidase DNA) were given orally to Wistar rats. Significant transgene expression (compared to background) was found in peripheral tissue (spleen) 72 h after administration. This work demonstrates the potential application of microparticle carriers for mucosal polyplex-based vaccination.