MOSFET-Embedded microcantilevers for measuring deflection in biomolecular sensors

A promising approach for detecting biomolecules follows their binding to immobilized probe molecules on microfabricated cantilevers; binding causes surface stresses that bend the cantilever. We measured this deflection, which is on the order of tens of nanometers, by embedding a metal-oxide semiconductor field-effect transistor (MOSFET) into the base of the cantilever and recording decreases in drain current with deflections as small as 5 nanometers. The gate region of the MOSFET responds to surface stresses and thus is embedded in silicon nitride so as to avoid direct contact with the sample solution. This approach, which offers low noise, high sensitivity, and direct readout, was used to detect specific binding events with biotin and antibodies.     

Correlation between spontaneous feeding behavior and neuropeptide Y profile in the third ventricular cerebrospinal fluid of goats

Feeding behavior is regulated by neural signals in the hypothalamus, but secretory activities of these signals in vivo and their relationship with spontaneous feeding remain to be solved. In the present study, we investigated the correlation between neuropeptide Y (NPY) and somatostatin (SRIF) profiles in cerebrospinal fluid (CSF) and spontaneous feeding behavior in goats. CSF samples were collected every 15 min for 8 h from the third ventricle and feeding behavior was observed throughout the experimental period. The spontaneous feeding behavior, the mean duration of which was 58 min, occurred with an interval of 146 min. NPY in the CSF fluctuated in an episodic fashion with a 145 min interval. Each NPY episode was followed by spontaneous feeding with a time lag of 24 min. SRIF levels in CSF changed more frequently in a pulsatile manner and were related to neither NPY profiles nor feeding behavior. These results suggest that NPY, but not SRIF, is a physiological signal to drive feeding in goats.     

Comparative effect of drought duration on growth,photosynthesis, water relations,and solute accumulation in wild and cultivated barley species

Drought is a major factor limiting crop production worldwide. Barley is a well‐adapted cereal that is largely grown on dry marginal land where water and salinity are the most prevalent environmental stresses. This study was carried out to investigate the effects of drought stress and subsequent recovery on growth, photosynthetic activity, water relations, osmotic adjustment (OA), and solute accumulation of wild (Hordeum maritimum) and cultivated barley (H. vulgare L.). In a pot experiment, 60 d old seedlings were subjected to drought stress for 0, 7, 14, 21, or 28 d, and then re‐watered to recover for up to 21 d. Plants were harvested at the end of each of these drought/recovery treatments. Drought significantly reduced fresh and dry weights at the whole‐plant level, photosynthetic activities, and solute and water potentials, while increasing leaf Na⁺ and K⁺ concentrations. The adverse effects of drought on growth were more marked in cultivated barley than in wild barley and the reverse was true for photosynthetic activities. During recovery, all wild barley seedlings completely recovered. For cultivated barley seedlings, rehydration had a beneficial effect on growth and photosynthesis, independent of treatment duration, but complete recovery did not occur. The reduction in leaf solute potential at full turgor in drought‐stressed barley, relative to the control, suggests active OA which was more significant in wild barley than in cultivated barley. OA was mainly due to the accumulation of inorganic (K⁺ in cultivated barley and Na⁺ in wild barley) and organic (soluble sugars and proline) solutes. The results suggest that OA is an important component of the drought‐stress adaptation mechanism in wild barley, but is not sufficient to contribute to drought tolerance in cultivated barley. In the latter species, the results show that even short periods (as little as 7 d) of water deficit stress had considerable long‐term effects on plant growth.     

Transient ischaemia affects plasma membrane glutamate transporter, not vesicular glutamate transporter, expressions in the gerbil hippocampus

In the present study, we investigated expressions of vesicular glutamate transporter (VGLUT) and of the plasma membrane glutamate transporters [glutamate transporter 1 (GLT-1), glutamate/aspartate transporter (GLAST) and excitatory amino acid carrier 1 (EAAC-1)] in the gerbil hippocampus following transient ischaemia. The expressional levels and distribution patterns of VGLUT immunoreactivities were unaltered until 3 days after ischaemic-insults. However, VGLUT-2 immunoreactivity in the CA1 region was reduced at 4 days after ischaemia due to delayed neuronal death. In addition, both GLT-1 and GLAST immunoreactivities in the CA1 region were enhanced at 30 min - 12 h after ischaemia-reperfusion and their expression began to reduce at 24 h after ischaemia-reperfusion. In contrast, EAAC-1 immunoreactivity was transiently reduced in the CA1 region at 30 min after ischaemia, re-enhanced at 3-12 h after ischaemia, and re-reduced at 24 h after ischaemia. These findings suggest that malfunctions of plasma membrane glutamate transporters, not of VGLUT, may play an important role in the elevation of extracellular glutamate concentration following ischaemic insults.     

Induced distal defence potentiation against Phytophthora sojae in soybean

Soybean phenylpropanoid defence responses to the wall glucan elicitor (WGE) fromPhytophthora sojae include the accumulation of phenolic polymers and glyceollin in cells immediately proximal to the point of treatment and the accumulation of conjugates of the isoflavones, daidzein and genistein, in distal cells. Since daidzein is a glyceollin precursor and genistein is both toxic to P. sojae and implicated in local potentiation of competency for the glyceollin response, it has been hypothesized that the distal cell response might raise the defence potential of cells distant from the infection court. In this paper, it is demonstrated that the WGE is indeed highly effective in protecting cells distal to the point of treatment from infection by P. sojae. Mycolaminaran, jasmonic acid (JA), methyl jasmonate and the ethylene precursor, 1-amino-cyclopropane carboxylic acid (ACC), are also effective, while salicylic acid (SA) is not. Methyl jasmonate, WGE and mycolaminaran are most effective, resulting in nearly complete protection against the pathogen even in the universally susceptible line, Williams. Dose response data revealed two distinct types of protection shared by all treatments. The first contains the pathogen to the point of inoculation, while the second is lesion limiting. Lesion limiting protection correlates very well with pre-infectional levels of genistein conjugates and accumulation of a specific peroxidase isozyme, P 2-4, and with post-infectional accumulation of glyceollin, suggesting that this type of protection may be the result of a distal potentiation of glyceollin elicitation competency. The mechanism underlying local containment protection is unknown, but it does not correlate well with any of the established phenylpropanoid responses.     

Sero-survey on Aino, Akabane, Chuzan, bovine ephemeral fever and Japanese encephalitis virus of cattle and swine in Korea

Vector-borne arboviruses produce mild to severe symptoms in domestic animals. Bovine ephemeral fever (BEF), Akabane, Aino, and Chuzan virus have been primarily attributed to reproductive disorders or febrile diseases in cattle, and Japanese encephalitis virus (JEV) is mainly associated with reproductive failures in swine. We investigated antibody titers from domestic swine against four bovine arboviruses (BEF, Akabane, Aino, and Chuzan virus) and from cattle against JEV in Korea. While the positive rates for Akabane and BEF were 37.4% and 15.7%, the positive incidence of Chuzan and Aino were relatively low, with positive rates of 3.04% and 0.4%, respectively, based on a virus neutralization assay. Antibody titers against more than one virus were also frequently detected in domestic swine. The incidence of JEV was 51.3% among domestic cattle. In addition, one positive case was detected in the thoracic fluids from 35 aborted calves, based on the hemagglutination inhibition test. Our results indicate that swine are susceptible hosts of bovine arboviruses without showing clinical symptoms in a natural environment. Moreover, we confirmed that JEV could be associated with reproductive failure in pregnant cattle, as were other vector-borne bovine arboviruses assessed in this study.     

Contribution of æ1-acid glycoprotein to plasma protein binding of some basic antimicrobials in pigs

Protein binding kinetics of basic antimicrobials including trimethoprim (TMP), erythromycin (EM), lincomycin (LM) and clindamycin (CM) were studied using porcine plasma, albumin and æ-acid glycoprotein (AGP). Rosenthal plots of these basic drugs in porcine plasma suggest saturable and non-saturable binding. Dissociation constants (K_d) and binding capacity (B_max) for saturable binding were as follows: TMP, K_d= 8.58 μmol/L, B_max= 5.26 μmol/L; EM, k_d= 2.72 μmol/L, B_max= 3.06 μmol/L; LM, k_d= 3.96 μmol/L, B_max= 6.58 μmol/L and CM, k_d= 4.43 μmol/L, B_max= 21.7 μmol/L. The proportionality constants (B_max2/k_d2) for non-saturable binding were 0.29 in TMP, 0.52 in EM, 0.17 in LM and 3.2 in CM. The k_ds of the drugs in porcine AGP solution were determined by a fluorescence quenching method, using 1-anilino-8-naphthalene sulphonate (ANS) as a fluorescent probe: 9.51 μmol/L in TMP, 1.89 μmol/ L in EM, 4.48 μmol/L in LM and 9.69 μmol/L, in CM. Comparable kd values between porcine plasma and AGP solution indicated that AGP is a major saturable binder in porcine plasma. Binding property to porcine albumin presented linearity, showing the following proportionality constants: 0.23 in TMP, 0.38 in EM, 0.01 in LM and 0.76 in CM. The comparable proportionality constants of TMP and EM between porcine plasma and albumin solution indicate that albumin is a major non-saturable binder, whereas proportionality constants of LM and CM in albumin solution compared to those in porcine plasma were low, implying another non-saturable binder, i.e. lipoprotein. Simulation curve of drug-binding percentage vs. AGP concentrations showed that in pigs under a pathologic state, or during early growth stage with high AGP levels, AGP could be a main contributor to drug-plasma protein binding for all drugs examined. The increase of AGP from normal to pathological concentrations induced a decrease in the unbound fraction: LM > CM > EM > TMP in order of AGP contribution to drug binding. Therefore, the disposition and efficacy of basic antimicrobials which bind to AGP with high affinity could be markedly influenced by altered AGP levels, implying AGP contribution to pharmacokinetics and pharmacodynamics.     

Beneficial effects of antioxidants in improving health conditions of sheep infected with foot-and-mouth disease

Tropical Animal Health and Production - The effect of multinutrient antioxidant treatment on sheep naturally infected with FMD virus was investigated in terms of general health conditions, serum...