Physiology of seawater acclimation in the striped bass,Morone saxatilis (Walbaum)

Several experiments were performed to investigate the physiology of seawater acclimation in the striped bass, Morone saxatilis. Transfer of fish from fresh water (FW) to seawater (SW; 31–32 ppt) induced only a minimal disturbance of osmotic homeostasis. Ambient salinity did not affect plasma thyroxine, but plasma cortisol remained elevated for 24h after SW transfer. Gill and opercular membrane chloride cell density and Na⁺,K⁺-ATPase activity were relatively high and unaffected by salinity. Average chloride cell size, however, was slightly increased (16%) in SW-acclimated fish. Gill succinate dehydrogenase activity was higher in SW-acclimated fish than in FW fish. Kidney Na⁺, K⁺-ATPase activity was slightly lower (16%) in SW fish than in FW fish. Posterior intestinal Na⁺,K⁺-ATPase activity and water transport capacity (J_v) did not change upon SW transfer, whereas middle intestinal Na⁺,K⁺-ATPase activity increased 35% after transfer and was correlated with an increase in J_v (110%). As salinity induced only minor changes in the osmoregulatory organs examined, it is proposed that the intrinsic euryhalinity of the striped bass may be related to a high degree of “preparedness” for hypoosmoregulation that is uncommon among teleosts studied to data.     

Composition and mechanism of antitumor effects of Hericium erinaceus mushroom extracts in tumor-bearing mice

We investigated antitumor effects of the following four extracts of freeze-dried Hericium erinaceus mushrooms in Balb/c mice intracutaneously transplanted on the backs with CT-26 colon cancer cells: HWE, hot water extraction by boiling in water for 3 h; MWE, microwaving in 50% ethanol/water at 60 W for 3 min; and ACE and AKE, boiling in 1% HCl or 3% NaOH for 2 h. HWE and MWE with a higher content of β-glucans, determined by an assay kit, than ACE and MKE were active in all bioassays. Gas chromatography/mass spectrometry analyses showed the presence of 40, 27, 16, and 13 compounds, respectively, in the four extracts. Daily intraperitoneal (ip) injections of HWE and MWE for 2 weeks significantly reduced tumor weights by 38 and 41%. Tumor regressions were associated with changes in the following cancer biomarkers as compared to phosphate buffer (PBS)-treated control mice: 2.7- and 2.4-fold increases in cytolytic activity of splenic natural killer (NK) cells; restored nitric oxide production and phagocytosis in peritoneal macrophages to 95-98% of normal levels; ～2-fold increase in released pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 from macrophages; and ～56 and ～60% reductions in the number of blood vessels inside the tumor. The pro-angiogenic factors vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2), and 5-lipoxygenase (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. Enzyme-linked immunosorbent assay of tumor cells confirmed reduced expression of COX-2 and 5-LOX (32 and 31%). Reduced COX-2 and 5-LOX expression down-regulated VEGF expression, resulting in inhibition of neo-angiogenesis inside the tumors. The results indicate that induction of NK activity, activation of macrophages, and inhibition of angiogenesis all contribute to the mechanism of reduction of tumor size.     

Toxic pneumonitis caused by inhalation of hydrocarbon waterproofing spray in two dogs

CASE DESCRIPTION: 2 dogs were evaluated because of vomiting and lethargy (a Toy Poodle; dog 1) and acute respiratory distress, vomiting, and anorexia (a Chihuahua; dog 2). Dog 1 had been exposed to a commercial hydrocarbon waterproofing spray 24 hours before the development of clinical signs, and dog 2 was examined 18 hours after exposure to a waterproofing spray containing heptane, a highly flammable liquid hydrocarbon. CLINICAL FINDINGS: In both dogs, major gastrointestinal tract abnormalities were ruled out but respiratory status worsened. Thoracic radiography revealed a diffuse interstitial pulmonary pattern, and hypoxemia was detected. TREATMENT AND OUTCOME: Hospitalization for monitoring and care was required for both dogs. The dogs recovered with supportive care, which included administration of oxygen, fluids, and bronchodilators. Additionally, dog 1 received glucocorticoids via inhalation and supplemental enteral nutrition, whereas dog 2 was treated with an antimicrobial. CLINICAL RELEVANCE: The dogs of this report developed hydrocarbon pneumonitis following exposure to waterproofing sprays. Such sprays contain potentially toxic hydrocarbons. The severity of the adverse effects associated with exposure may have been amplified because the dogs were physically small and were exposed to a relatively large amount of aerosolized spray within small areas. Development of chemical pneumonitis in pet animals is best prevented by application of waterproofing sprays in well-ventilated or outdoor areas from which pets have been excluded. With prolonged hospitalization and considerable monitoring and care, affected dogs can recover from these exposures.     

The effect of temperature on the energy budget of the Manila clam, <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis>

In this study, the energy budget of the Manila clam, Ruditapes philippinarum, was evaluated after one-week acclimation periods at 5, 10, 15, 20, and 25°C. Small clams (151 ± 12 mg DW) and large clams (353 ± 16 mg DW) were fed with the microalgae, Isochrysis galbana. Filtration rate, ingestion rate, assimilation efficiency, oxygen-consumption rate, and ammonia excretion rate were measured. Both filtration rate and ingestion rate of small and large clams were found to be related to temperature. The highest Q ₁₀ values were measured in the range 15–20°C for both small and large clams. Assimilation efficiency of both small and large clams was not significantly influenced by temperature, although the maximum mean values were detected at 20°C. Oxygen consumption rate and ammonia excretion rate of small and large clams were found to be related directly to temperature over the entire range, with a maximum being detected at 25°C. The highest Q ₁₀ value was estimated in the range 10–15°C with regard to oxygen consumption rate, and in the range of 15–20°C with regard to ammonia excretion rate. Scope for growth (SFG) was positive at all temperatures, achieving a maximum value at 20°C in both small and large clams, primarily as a consequence of the enhanced ingestion rate which offset the concomitant elevation in the metabolic rate. In this study we have estimated the thermal optimum for this species at 20°C.     

Pterocarpan profiles for soybean leaves at different growth stages and investigation of their glycosidase inhibitions

Soybean leaves are eaten as seasonal edible greens in Korea. Analysis of the ethyl acetate extract of these leaves showed that it exhibited potent and selective neuraminidase inhibition, which began at the R3 stage and peaked at R7. Ten pterocarpans, including the new 6a-hydroxypterocarpan 10, were isolated from soybean leaves and their inhibition activities tested against a range of glycosidases. The relationship between structure and enzyme inhibition was investigated: 6a-hydroxypterocarpans exhibited much higher inhibition against neuraminidase (IC(50) = 2.4-89.4 μM) than α-glucosidase (IC(50) = 90.4-?>100 μM). Glyceollin VII (7) displayed 40-fold greater activity (IC(50) = 2.4 μM) against neuraminidase than α-glucosidase (IC(50) = 90.4 μM). On the other hand, coumestanes (1-3) were good α-glucosidase inhibitors (IC(50) = 6.0-42.6 μM). In kinetic analysis, the most potent neuraminidase inhibitors (5-10) were noncompetitive. HPLC analysis indicated that most pterocarpan synthesis began from the R3 stage, and a rapid change of pterocarpan concentrations was observed between the R4 and R7 stages.     

Does the Presence of Detached Root Border Cells of Zea mays Alter the Activity of the Pathogenic Nematode Meloidogyne incognita?

ABSTRACT The root-knot nematode Meloidogyne incognita is a major pathogen of a range of important crops. Currently, control is typically achieved by the use of nematicides. However, recent work suggests that manipulating the ability of roots to slough off border cells, which then act as a decoy to the nematode, can significantly decrease damage to the roots. We investigated the attractiveness of border cells to M. incognita and the response of the nematode to border cells in close proximity. We found very limited attraction, in that nematodes did not preferentially alter direction to move toward the border cells, but a large and significant increase in nematode speed was observed once they were in the immediate vicinity of border cells. We discuss the results in the context of physical and biological mechanisms in relation to the control of pathogenic nematodes.     

Analysis of the toxic potential of Palicourea corymbifera (Müll. Arg.) Standl. in laboratory animals

Palicourea species may produce bovine toxicity. Palicourea corymbifera grows in terra firme forests within the Amazon rain forest and in Tropical America, particularly in spots that gave place to gazing areas. The lyophilized extract done with the aerial organs of P. corymbifera were analyzed in male and female mice. Results revealed a significant toxicity: LD50 was 1.10 (1.04-1.15)g/kg for male mice, and 1.05 (1.00-1.10)g/kg for female mice. Locomotion was affected as well as there were reflexes linked to environmental stimuli in addition to changes in posture. Progressive central nervous system stimulus signs such as trembling and convulsions were detected, the latter followed by the animal's death. Macroscopic histopathological exams performed on the liver, kidneys and lungs of mice submitted to necropsy did not indicate the existence of lesions. General activity of animals, measured in an open field, was reduced as a result of the administration of the extract. Duration of locomotion and rearing frequency were reduced, in opposition to an increase in the duration of immobility. Thin layer chromatography analysis showed that monofluoroacetic acid is present in the lyophilized extract, but other qualitative techniques as gas chromatography/mass spectrometry and 19F nuclear magnetic resonance showed that the MFAA was not present in the extract, and that the toxicity is related to other compound, although the toxic profile is very similar to that of MFAA. P. corymbifera was shown to be significantly toxic to laboratory animals and investigation of the possible toxic substance shall be done.