Deleterious effects of non-native species introduced into Lake Victoria, East Africa

Lake Victoria, in East Africa, has suffered from introductions and invasions of non-native species such as Lates niloticus, various tilapiine species, and Eichornia crassipes since the 1950s. These have had a devastating effect on the natural biological communities. This paper reviews the effects of the introductions on ecology, environment, fisheries and the local human population.

Bilateral high-frequency stimulation of the subthalamic nucleus on attentional performance: transient deleterious effects and enhanced motivation in both intact and parkinsonian rats.

It is now well established that subthalamic nucleus high-frequency stimulation (STN HFS) alleviates motor problems in Parkinson's disease. However, its efficacy for cognitive function remains a matter of debate. The aim of this study was to assess the effects of STN HFS in rats performing a visual attentional task. Bilateral STN HFS was applied in intact and in bilaterally dopamine (DA)-depleted rats. In all animals, STN HFS had a transient debilitating effect on all the variables measured in the task. In DA-depleted rats, STN HFS did not alleviate the deficits induced by the DA lesion such as omissions and latency to make correct responses, but induced perseverative approaches to the food magazine, an indicator of enhanced motivation. In sham-operated controls, STN HFS significantly reduced accuracy and induced perseverative behaviour, mimicking partially the effects of bilateral STN lesions in the same task. These results are in line with the hypothesis that STN HFS only partially mimics inactivation of STN produced by lesioning and confirm the motivational exacerbation induced by STN inactivation.

Phytoremediation Potential of Mana-Cubiu (Solanum sessiliflorum Dunal) for the Deleterious Effects of Methylmercury on the Reproductive System of Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Deleterious effects of low level of vitamin E and high stocking density on the hematology response of pacus, during chronic inflammatory reaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Topical curcumin can inhibit deleterious effects of upper respiratory tract bacteria on human oropharyngeal cells in vitro: potential role for patients with cancer therapy induced mucositis?

Curcumin exerts its anti-inflammatory activity via inhibition of nuclear factor κB. Oropharyngeal epithelia and residing bacteria closely interact in inflammation and infection. This in vitro model investigated the effects of curcumin on bacterial survival, adherence to, and invasion of upper respiratory tract epithelia, and studied its anti-inflammatory effect. We aimed to establish a model, which could offer insights into the host-pathogen interaction in cancer therapy induced mucositis.

Deleterious effects of roving on learned tasks

In typical perceptual learning experiments, one stimulus type (e.g., a bisection stimulus offset either to the left or right) is presented per trial. In roving, two different stimulus types (e.g., a 30′ and a 20′ wide bisection stimulus) are randomly interleaved from trial to trial. Roving can impair both perceptual learning and task sensitivity. Here, we investigate the relationship between the two. Using a bisection task, we found no effect of roving before training. We next trained subjects and they improved. A roving condition applied after training impaired sensitivity.

Deleterious Effects of Lard-enriched Diet on Tissues Fatty Acids Composition and Hypothalamic Insulin Actions

Altered tissue fatty acid (FA) composition may affect mechanisms involved in the control of energy homeostasis, including central insulin actions. In rats fed either standard chow or a lard-enriched chow (high in saturated/low in polyunsaturated FA, HS-LP) for eight weeks, we examined the FA composition of blood, hypothalamus, liver, and retroperitoneal, epididymal and mesenteric adipose tissues. Insulin-induced hypophagia and hypothalamic signaling were evaluated after intracerebroventricular insulin injection. HS-LP feeding increased saturated FA content in adipose tissues and serum while it decreased polyunsaturated FA content of adipose tissues, serum, and liver. Hypothalamic C20:5n-3 and C20:3n-6 contents increased while monounsaturated FA content decreased. HS-LP rats showed hyperglycemia, impaired insulin-induced hypophagia and hypothalamic insulin signaling. The results showed that, upon HS-LP feeding, peripheral tissues underwent potentially deleterious alterations in their FA composition, whist the hypothalamus was relatively preserved. However, hypothalamic insulin signaling and hypophagia were drastically impaired. These findings suggest that impairment of hypothalamic insulin actions by HS-LP feeding was not related to tissue FA composition.

Mice lacking β-Adrenergic receptors have increased bone mass but are not protected from deleterious skeletal effects of ovariectomy

Activation of β2-adrenergic receptors inhibits osteoblastic bone formation and enhances osteoclastic bone resorption. Whether β-blockers inhibit ovariectomy-induced bone loss and decrease fracture risk remains controversial. To further explore the role of β-adrenergic signaling in skeletal acquisition and response to estrogen deficiency, we evaluated mice lacking the three known β-adrenergic receptors (β-less). Body weight, percent fat, and bone mineral density were significantly higher in male β-less than wild-type (WT) mice, more so with increasing age. Consistent with their greater fat mass, serum leptin was significantly higher in β-less than WT mice. Mid-femoral cross-sectional area and cortical thickness were significantly higher in adult β-less than WT mice, as were femoral biomechanical properties (+28 to +49%, P < 0.01). Young male β-less had higher vertebral (1.3-fold) and distal femoral (3.5-fold) trabecular bone volume than WT (P < 0.001 for both) and lower osteoclast surface. With aging, these differences lessened, with histological evidence of increased osteoclast surface and decreased bone formation rate at the distal femur in β-less vs. WT mice. Serum tartrate-resistance alkaline phosphatase-5B was elevated in β-less compared with WT mice from 8–16 wk of age (P < 0.01). Ovariectomy inhibited bone mass gain and decreased trabecular bone volume/total volume similarly in β-less and WT mice. Altogether, these data indicate that absence of β-adrenergic signaling results in obesity and increased cortical bone mass in males but does not prevent deleterious effects of estrogen deficiency on trabecular bone microarchitecture. Our findings also suggest direct positive effects of weight and/or leptin on bone turnover and cortical bone structure, independent of adrenergic signaling.

In vitro antioxidant and in vivo prophylactic effects of two gamma-lactones isolated from Grewia tiliaefolia against hepatotoxicity in carbon tetrachloride intoxicated rats

Grewia tiliaefolia is widely used in traditional Indian medicines to cure jaundice, biliousness, dysentery and the diseases of blood. Bioassay-guided fractionation of methanolic extract of the G. tiliaefolia bark has resulted in the isolation of D-erythro-2-hexenoic acid gamma-lactone (EHGL) and gulonic acid gamma-lactone (GAGL). Hepatoprotective activity of the methanolic extract and the isolated constituents were evaluated against CCl4-induced hepatotoxicity in rats. The treatment with methanolic extract, EHGL and GAGL at oral doses of 100, 150 and 60 mg/kg respectively with concomitant CCl4 intraperitoneal injection (I ml/kg) significantly reduced the elevated plasma levels of aminotransferases, alkaline phosphatase and the incidence of liver necrosis compared with the CCl4-injected group without affecting the concentrations of serum bilirubin and hepatic markers. EHGL and GAGL significantly inhibited the elevated levels of thiobarbituric acid reactive substances and glutathione in liver homogenates. Histology of the liver tissues of the extract and isolated constituents treated groups showed the presence of normal hepatic cords, absence of necrosis and fatty infiltration as similar to the normal control. The results revealed that the hepatoprotective activity of EHGL is significant as similar to the standard drug silymarin. To clarify the influence of the extract and isolated constituents on the protection of oxidative-hepatic damage, we examined in vitro antioxidant properties of the test compounds. The extract and the constituents showed significant free radical scavenging activity. These results suggest that the extract as well as the constituents could protect the hepatocytes from CCl4-induced liver damage perhaps, by their anti-oxidative effect on hepatocytes, hence eliminating the deleterious effects of toxic metabolites from CCl4, (C) 2009 Elsevier B.V. All rights reserved.

Florida's West Coast inlets: shoreline effects and recommended action

This report responds to the 1986 Beaches Bill which, in recognition of the potential deleterious impact on Florida's beaches of inlets modified for navigation, mandated a study of those inlets with identification of recommended action to reduce the impacts. This report addresses west Coast inlets; East Coast inlets are the subject of a companion report. There are 37 inlets along that portion of Florida's West Coast commencing from Pensacola Bay Entrance to Caxambas Pass at the south end of Marco Island. Compared to those on the East Coast, most West Coast inlets have not had the deleterious effects on the adjacent beaches, yet all modified inlets without proper management have the potential of impacting unfavorably on the adjacent shorelines. Moreover, at present there is interest in opening three West Coast entrances which either have been open in the past (Midnight Pass) or which have opened occasionally (Navarre Pass and Entrance to Phillips Lake). A review of inlets in their natural condition demonstrates the presence of a shallow broad outer bar across which the longshore transport Occurs. These shallow and shifting bar features were unsuitable for navigation which in many cases has led to the deepening of the channels and fixing with one or two jetty structures. Inlets in this modified state along with inappropriate maintenance practices have the potential of placing great ero$ional stress along the adjacent beaches. Moreover. channel dredging can reduce wave sheltering of the shoreline by ebb tidal shoals and alter the equilibrium of the affected shoreline segments. The ultimate in poor sand management practice is the placement of good quality beach sand in water depths too great for the sand to reenter the longshore system under natural forces; depths of 12 ft. or less are considered appropriate for Florida in order to maintain the sand in the system. With the interference of the nearshore sediment transport processes by inlets modified for navigation, if the adjacent beaches are to be stabilized there must be an active monitoring program with commitment to placement of dredged material of beach quality on shoreline segments of documented need. Several East Coast inlets have such transfer facilities; however. the quantities of sand transferred should be increased. Although an evolution and improvement in the technical capability to manage sand resources in the vicinity of inlets is expected, an adequate capability exists today and a concerted program should be made to commence a scheduled implementation of this capability at those entrances causing greatest erosional stress on the adjacent shorelines. A brief summary review for each of the 37 West Coast inlets is presented including: a scaled aerial photograph, brief historical information, several items related to sediment losses at each inlet and special characteristics relevant to State responsibilities. For each inlet, where appropriate, the above infor~tion is utilized to develop a recommenced action. (PDF has 101 pages.)

The effects of stress on benthic algal communities

The effects of stress on both microalgal and macroalgal communities are considered. On one hand the contrasting approaches of studies of these two communities reflect intrinsic differences in plant size, longevity and ease of handling. On the other hand they reveal that biological monitoring of the potentially deleterious effects of man's activities has focused largely on freshwater environments in which macroalgae only occasionally dominate. Large conspicuous plants can be readily investigated as individuals, whereas it is virtually impossible to trace effects of stress on an individual cell of a vegetatively-reproducing microalga; a population approach is almost inevitably necessary. However, rapid turnover rates, a spectrum of ecological characteristics distributed between many taxa, and the potential for statistical analysis, have facilitated the use of microalgae in environmental impact studies. Failure to extend such investigations into marine systems rests as much on man's ability to ignore environmental deterioration until it affects his quality of life as on the visual dominance of seaweeds around our coasts. However, large gaps remain in our knowledge of both large and small algae; some reported community changes over time are suspect, and the causes of even blatant changes are not always apparent.