Seasonal bioaerosol load and statistical analysis within different microenvironments of an academic institute situated in the Indo-Gangetic Plain

Aerobiologia - Bioaerosols have gained importance in atmospheric sciences in the past few decades. Their exposure upsurges the health problems in sensitive population and is also known to...     

The role of vitellogenin during gestation of Girardinichthys viviparus and Ameca splendens; two goodeid fish with matrotrophic viviparity

Goodeid fish have matrotrophic viviparity, and unlike lecitotrophic fish, yolk loss forces the female to provide the nutritional requirements for embryonic development. Vitellogenin (VTG) is the yolk precursor protein synthesized in the maternal liver, but there is only circumstantial evidence regarding VTG supply during the ontogenesis of bony fish with matrotrophic viviparity. Therefore, the goal of the present study was to identify and quantify VTG during gestation of the black fin goodeid Girardinichthys viviparus and the butterfly split-fin goodeid Ameca splendens. Females at different gonadic developmental stages were selected in order to evaluate VTG mRNA expression in the maternal liver using RT-PCR; VTG quantification in maternal muscle and liver, as well as in the embryos, was done using ELISA, and immunohistochemical detection of VTG was done in the black fin goodeid. The results suggest that VTG supplies nutrients during embryonic development of both species, which have different life histories. It is possible that the transition from lecitotrophy to matrotrophic viviparity in bony fish with intraluminal gestation involved adaptive transition strategies that included changes in the relationship between oocytes and follicular cells, as well as a gradual loss of VTG synthesis during embryonic development.     

Quantification and characterization of vegetation and functional trait diversity of the riparian zones in protected forest of Kashmir Himalaya,India

Globally, riparian zones along river banks are widely recognized for their vital role in water regulation and conservation of biodiversity. Here, we specifically investigated the floristic and functional diversity of the vegetation of the riparian zones of protected forests in Kashmir Himalaya, India. A random sampling method was used for site selection while a transect method was used for data collection. Data obtained from the field was subjected to taxonomic and functional classification. Floristic analysis revealed a total of 78 species belonging to 68 genera in 40 families, suggesting an unequal distribution of species among families. Nine families contributed half of the species: Rosaceae was the dominant family with nine (12%) species followed by Asteraceae with eight species (10%), while 23 families were monotypic. In terms of functional trait diversity, herbaceous and perennial taxa dominated, and the biological spectrum showed a dominance of the therophytic life form, indicative of disturbed vegetation. The phenological spectrum revealed that the maximum flowering periods starts in March and extends into May, in which a total of 61% of the species were observed to flower. The leading leaf size spectra were mesophyll with 35%, followed by microphyll (31%). Most (64%) of the species had a simple leaf lamina type. The results of the present study serve as a means to evaluate best management practices, assess restoration and mitigation projects, prioritize riparian related resource management decisions, and establish aquatic life use standards.     

Oligonucleotide probes applied for sensitive enzyme-amplified electrochemical assay of mercury(II) ions

We developed a novel electrochemical sensor for Hg(2+) detection using two mercury-specific oligonucleotide probes and streptavidin-horseradish peroxidase (HRP) enzymatic signal amplification. The two mercury-specific oligonucleotide probes comprised a thiolated capture probe and a biotinated signal probe. The thiolated capture probe was immobilized on a gold electrode. In the presence of Hg(2+), the thymine-Hg(2+)-thymine (T-Hg(2+)-T) interaction between the mismatched T-T base pairs directed the biotinated signal probe hybridizing to the capture probe and yielded a biotin-functioned electrode surface. HRP was then immobilized on the biotin-modified substrate via biotin-streptavidin interaction. The immobilized HRP catalyzed the oxidation of hydroquinone (H(2)Q) to benzoquinone (BQ) by hydrogen peroxide (H(2)O(2)) and the generated BQ was further electrochemically reduced at the modified gold electrode, producing a readout signal for quantitative detection of Hg(2+). The results showed that the enzyme-amplified electrochemical sensor system was highly sensitive to Hg(2+) in the concentration of 0.5 nM to 1 μM with a detection limit of 0.3 nM, and it also demonstrated excellent selectivity against other interferential metal ions.     

Cost-effectiveness of second-line antihyperglycemic therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin

Background:

Metformin is widely accepted as first-line pharmacotherapy for patients with type 2 diabetes mellitus when glycemic control cannot be achieved by lifestyle interventions alone. However, uncertainty exists regarding the optimal second-line therapy for patients whose diabetes is inadequately controlled by metformin monotherapy. Increased use of newer, more costly agents, along with the rising incidence of type 2 diabetes, carries significant budgetary implications for health care systems. We conducted this analysis to determine the relative costs, benefits and cost-effectiveness of options for second-line treatment of type 2 diabetes.

Methods:

We used the United Kingdom Prospective Diabetes Study Outcomes Model to forecast diabetes-related complications, quality-adjusted life-years and costs of alternative second-line therapies available in Canada for adults with type 2 diabetes inadequately controlled by metformin. We obtained clinical data from a systematic review and mixed treatment comparison meta-analysis, and we obtained information on costs and utilities from published sources. We performed extensive sensitivity analyses to test the robustness of results to variation in inputs and assumptions.

Results:

Sulphonylureas, when added to metformin, were associated with the most favourable cost-effectiveness estimate, with an incremental cost of $12 757 per quality-adjusted life-year gained, relative to continued metformin monotherapy. Treatment with other agents, including thiazolidinediones and dipeptidyl peptidase-4 inhibitors, had unfavourable cost-effectiveness estimates compared with sulphonylureas. These results were robust to extensive sensitivity analyses.

Interpretation:

For most patients with type 2 diabetes that is inadequately controlled with metformin monotherapy, the addition of a sulphonylurea represents the most cost-effective second-line therapy.Type 2 diabetes mellitus is a progressive disease typically treated in a stepwise fashion, beginning with lifestyle modification, followed by the addition of one or more oral antihyperglycemic drugs and, finally, administration of exogenous insulin. Metformin monotherapy is widely recommended as first-line pharmacotherapy,^1,2 given its favourable effects in controlling blood glucose and body weight, low risk of hypoglycemia, low cost and association with mortality benefit.³ Multiple second-line treatment strategies are available for patients in whom glycemic control has become inadequate. These approaches are typically used in addition to continued metformin therapy.^4,5 Numerous second-line agents are available in Canada, including older oral agents, such as sulphonylureas, and more recently introduced agents, such as thiazolidinediones and dipeptidyl peptidase-4 inhibitors.The large number of choices for second-line therapy has increased uncertainty regarding the optimal treatment pathway. Recent clinical practice guidelines, including those produced by the Canadian Diabetes Association¹ and by the American Diabetes Association and the European Association for the Study of Diabetes,² have suggested selecting from among several agents on the basis of their respective advantages and disadvantages. There has been a considerable increase in the use of newer, more costly oral antihyperglycemic agents, which has resulted in substantial increases in associated costs to patients and both public and private drug plans in Canada.⁴ In light of current therapeutic uncertainty, the large proportion of patients requiring second-line therapy over time^3,6 and the increasing prevalence of type 2 diabetes,⁷ the utilization and cost of second-line therapy are likely to continue to grow.Informed decisions regarding optimal prescribing and reimbursement of second-line agents by public and private health care payers requires information about clinical benefits, costs and cost-effectiveness.⁸ As part of a larger initiative to determine optimal prescribing of antihyperglycemic agents, we sought to determine the incremental cost-effectiveness of treatment with alternative second-line agents added to metformin in patients with type 2 diabetes no longer adequately controlled by metformin monotherapy.     

Isolation and primary culture of Necturus maculosus (Amphibia: urodela) hepatocytes

Summary In order to evaluate their suitability for physiological and ecotoxicological studies, hepatocytes were isolated from the common mudpuppy (Necturus maculosus) using a two-step collagenase perfusion. Hepatocytes in primary culture were investigated for 14 d using light and electron microscopy and biochemical analyses. A typical perfusion yielded 1.7×10⁵ viable hepatocytes per gram body weight with an average viability of 86±5%. The majority of isolated cells remained in suspension and formed aggregates. The viability of hepatocytes in primary culture was dependent on a fetal calf serum (FCS) concentration and incubation temperature. Viability was best at 8°C in Leibovitz L-15 medium supplemented with 5% FCS. The ultrastructural characteristics of freshly isolated hepatocytes resembled those of N. maculosus hepatocytes in vivo. Whereas hepatocyte viability remained relatively stable (around 80%) up to 14 d in culture, electron microscopic analyses revealed changes at ultrastructural level. The majority of hepatocytes retained similar structural characteristics to those in vivo up to 4 d. Loss of cellular polarity, fractionation of rough endoplasmic reticulum, formation of autophagosomes, and successive exhaustion of cellular glycogen deposits were observed with increased time in culture. Functional integrity, as estimated by tyrosine aminotransferase induction, decreased during the culture period. Ultrastructural and biochemical analyses indicate the need for further improvement of culture conditions. Nevertheless, isolated hepatocytes in primary culture for up to 4 d can be recommended as a model for physiological and toxicological studies in lower vertebrates.     

Morphological differences in the skin of marble trout Salmo marmoratus and of brown trout Salmo trutta

Despite being genetically very closely related, the marble trout Salmo marmoratus and the brown trout Salmo trutta exhibit marked phenotypic differences, particularly with regard to skin pigmentation. Histological analysis of skin from the head and gill cover of differently aged individuals of the two species was carried out in order to characterize differences in skin structure. The basic structure of skin of the individuals studied corresponded with that described for other salmonids, though the head epidermis was somewhat thicker in S. marmoratus than in S. trutta, thickening with age in both species. Numerous secretory goblet cells and sporadic secretory sacciform cells were observed in the upper and middle part of the epidermis in both species. Melanophores were present in both species only in the dermis, and were bigger in S. marmoratus and present at lower average density than in S. trutta, and more or less constant across all age classes. In adult S. marmoratus with fully established marble pigmentation, light areas at low density with small (i.e. aggregated) melanophores were present, while in S. trutta melanophores were more uniformly distributed.     

Prediction of the changes in thermodynamic stability of proteins caused by single amino acid substitutions

The functional (synthetic) activity of blood lymphocytes and bone marrow hematopoietic cells in ground squirrels was studied in different seasons and at different stages of the torpor-arousal cycle. The effect of γ-irradiation on animals in different physiological states was also studied. The synthetic activity of cells was estimated from the amount of active RNA per unit DNA in the cell (parameter α). The α values in lymphocytes were minimal in hibernating animals (January–March), reached a peak upon their complete awakening (April), slightly decreased in the summer activity period, and decreased further in the prehibernation autumn period (November). During winter arousals between torpor bouts, this parameter reached the same values as in summer. The dynamics of parameter α in bone marrow hematopoietic cells were generally similar: minimal values in November and higher between torpor bouts than in summer. The peak of synthetic activity of proliferating hematopoietic cells recorded upon awakening from hibernation in April was mainly due to the accumulation of cells in the G₁ and G₂ phases of the cell cycle, and its decrease in summer reflected prevalent transition from G₂ to mitosis and then partly to G₀. In the torpor-arousal-euthermia cycle, two stages of awakening were distinguished, differing considerably in most of the test parameters. The synthetic activity and the total number of blood and bone marrow cells in ground squirrels irradiated in the state of torpor did not differ significantly from those in nonirradiated torpid animals. The adverse effect of radiation in animals irradiated at the initial stage of awakening was lesser than in animals irradiated in the active state, whereas animals at the second stage of awakening proved more vulnerable to acute irradiation. The physiological state of ground squirrels exposed to ionizing radiation at different phases of the torpor-arousal-euthermia cycle plays a key role in the dynamics of qualitative and quantitative characteristics of blood system cells. The results of this study indicate that the hypometabolic state of ground squirrels during hibernation is a factor of protection from the impact of ionizing radiation on the whole body and on the immune system in particular.     

Association of ebola virus matrix protein VP40 with microtubules

Viruses exploit a variety of cellular components to complete their life cycles, and it has become increasingly clear that use of host cell microtubules is a vital part of the infection process for many viruses. A variety of viral proteins have been identified that interact with microtubules, either directly or via a microtubule-associated motor protein. Here, we report that Ebola virus associates with microtubules via the matrix protein VP40. When transfected into mammalian cells, a fraction of VP40 colocalized with microtubule bundles and VP40 coimmunoprecipitated with tubulin. The degree of colocalization and microtubule bundling in cells was markedly intensified by truncation of the C terminus to a length of 317 amino acids. Further truncation to 308 or fewer amino acids abolished the association with microtubules. Both the full-length and the 317-amino-acid truncation mutant stabilized microtubules against depolymerization with nocodazole. Direct physical interaction between purified VP40 and tubulin proteins was demonstrated in vitro. A region of moderate homology to the tubulin binding motif of the microtubule-associated protein MAP2 was identified in VP40. Deleting this region resulted in loss of microtubule stabilization against drug-induced depolymerization. The presence of VP40-associated microtubules in cells continuously treated with nocodazole suggested that VP40 promotes tubulin polymerization. Using an in vitro polymerization assay, we demonstrated that VP40 directly enhances tubulin polymerization without any cellular mediators. These results suggest that microtubules may play an important role in the Ebola virus life cycle and potentially provide a novel target for therapeutic intervention against this highly pathogenic virus.