Separation of signal transduction and adaptation functions of the aspartate receptor in bacterial sensing

In order to investigate the functions of stimulus recognition, signal transduction, and adaptation, the aspartate receptor gene for bacterial chemotaxis in Salmonella typhimurium has been sequenced and modified. A carboxyl-terminal truncated receptor was shown to bind aspartate and to transmit a signal to change motility behavior. However, the truncated receptor showed greatly reduced methyl-accepting capacity, and did not allow adaptation to the sensory stimulation. The separation of receptor functions by alteration of primary structure emphasizes that the receptor is directly involved in adaptation and is not solely a device for transmitting a signal across a membrane.     

Residue study of ivermectin in plasma,milk, and mozzarella cheese following subcutaneous administration to buffalo (Bubalus bubalis)

The distribution of ivermectin in buffalo plasma and milk after administration of a single subcutaneous dose (0.2 mg kg(-)(1) b.w.) was studied. Ivermectin reached the maximal concentration in plasma (28.5 +/- 1.7 ng mL(-)(1)) and milk (23.6 +/- 2.6 ng mL(-)(1)) after 2.4 +/- 0.32 and 2.8 +/- 0.44 days, respectively. The drug showed a parallel disposition in milk and plasma, with a ratio of 1.12 +/- 0.16. Ivermectin concentrations were detected in mozzarella cheese obtained from milk collected on days 1, 3, 4, and 20 following administration. The highest values (81.4 +/- 3.26 ng g(-)(1)) were found in the cheese produced on day 3 and were 4-fold higher than those present in the milk.     

Neuropharmacology of the essential oil of bergamot

Bergamot (Citrus bergamia, Risso) is a fruit most knowledgeable for its essential oil (BEO) used in aromatherapy to minimize symptoms of stress-induced anxiety and mild mood disorders and cancer pain though the rational basis for such applications awaits to be discovered. The behavioural and EEG spectrum power effects of BEO correlate well with its exocytotic and carrier-mediated release of discrete amino acids endowed with neurotransmitter function in the mammalian hippocampus supporting the deduction that BEO is able to interfere with normal and pathological synaptic plasticity. The observed neuroprotection in the course of experimental brain ischemia and pain does support this view. In conclusion, the data yielded so far contribute to our understanding of the mode of action of this phytocomplex on nerve tissue under normal and pathological experimental conditions and provide a rational basis for the practical use of BEO in complementary medicine. The opening of a wide venue for future research and translation into clinical settings is also envisaged.     

Senescence in sweet corn as influenced by phosphorous nutrition 1

Nutrient availability can affect the onset of senescence. Phosphate‐phosphorus (P) was added at the recommended and five times the recommended level to a Bernow fine‐loamy, siliceous, thermic Glossic Paleudalf soil at Lane, OK. Senescence in stalk and shank internodes and cobs was rated in shrunken‐2 sweet corn (Zea mays L.) cultivars at various developmental stages. Plant dry weight was determined at fresh market harvest. Stalk internode senescence rating increased through harvest. The internode subtending the ear node was almost completely senescent at anthesis. There were statistical, but likely not biologically important, differences in stalk internode senescence between cultivars. Increased P occasionally increased stalk internode senescence rating and reduced plant dry weight. Increased P either decreased, or had no effect on, shank internode or cob senescence.     

Essential role of BDNF in the mesolimbic dopamine pathway in social defeat stress

Mice experiencing repeated aggression develop a long-lasting aversion to social contact, which can be normalized by chronic, but not acute, administration of antidepressant. Using viral-mediated, mesolimbic dopamine pathway-specific knockdown of brain-derived neurotrophic factor (BDNF), we showed that BDNF is required for the development of this experience-dependent social aversion. Gene profiling in the nucleus accumbens indicates that local knockdown of BDNF obliterates most of the effects of repeated aggression on gene expression within this circuit, with similar effects being produced by chronic treatment with antidepressant. These results establish an essential role for BDNF in mediating long-term neural and behavioral plasticity in response to aversive social experiences.     

Anaerobic metabolism during short and long term storage of kiwifruit

Kiwifruit were stored in 0.25% O₂ (ULO), 1% O₂ (LO) and 2% O₂ + 5% CO₂ (CA) and the controls were kept in air. The fruit were held at 0 °C for 34 and 94 d of storage and, after these times, were transferred to 20 °C in air for 14 d of shelf life. During the short term storage (34 d), a significant increase in anaerobic metabolites, above all ethanol, was observed in ULO, LO, and CA fruit (166, 131, 120 μL/L). After the shift to shelf life, a large and unexpected increase in PDC (pyruvate decarboxylase), ADH (alcohol dehydrogenase in the direction of ethanol oxidation), LDH (lactate dehydrogenase), and GPT (glutamate-pyruvate transaminase) was observed, resulting in ethanol depletion (ULO) or no further increase, and an increase in acetaldehyde which, in turn, could have hastened fruit ripening. Even the control fruit showed an increase in ethanol during storage and an increase in enzyme activity during shelf life, especially in ADH, but to a lesser extent without an increase in acetaldehyde. During the long term storage, anaerobic metabolites (ethanol and acetaldehyde) still increased and GPT activity rose significantly in the ULO and CA samples. A burst of enzyme activity was also observed during the second shelf life in the CA and LO samples, but not in the control, while in ULO fruit the activity rose continuously. GPT activity showed the highest peaks in CA and ULO fruit. An ethylene burst was observed in ULO and CA fruit during the second shelf life (about 25 μL/kg-h) but not during the first shelf life. The potential role of these enzymes in kiwifruit stress response during storage and shelf life is discussed.     

Stomach wall evaluation using helical hydro-computed tomography

In helical hydro-computed tomography (helical hydro-CT), water is used as a neutral luminal contrast medium together with intravenous iodine contrast medium for the diagnosis and staging of human gastric neoplasia. We evaluated the feasibility of helical hydro-CT in 11 healthy animals (nine dogs and two cats). Adequate uniform gastric distension was obtained with 30 ml water/kg body weight. Fourteen client-owned dogs and four cats with suspected or diagnosed gastric neoplasia then underwent helical hydro-CT followed by intravenous contrast medium administration. Focal thickening with moderate contrast enhancement was found in 10 dogs and 3 cats. The extent of the lesion was assessed easily in all these patients. Three dogs and one cat had a normal stomach wall. One dog had multifocal thickening of the antrum but no histopathologic diagnosis was made. Helical hydro-CT, followed by intravenous contrast medium administration, is a simple technique for assessing the stomach wall.     

Three-dimensional microvascolature remodeling study of pig periovulatory follicles using vascular corrosion casts

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