Heterogeneous zonal distribution of sulfotransferase isoenzymes in rat liver

By employing dual-digitonin-pulse perfusion technique, the cytosolic fractions were prepared from periportal (PP) and perivenous (PV) hepatocytes of male and female rat livers. Sulfotransferase (ST) activities toward 2-naphthol (2NAP) (at pH 5.5 and 7.4), 4-nitrophenol, dehydroepiandrosterone (DHEA), and cortisol were measured in each fraction. DHEA-ST activity was mainly localized in PP fraction in males, while in females it was slightly higher in PP fraction than in PV samples. In contrast, phenol ST activities were higher in PV fraction in both sexes. With anti-HS-ST and anti-P-ST antisera, the levels of immunoreactive ST polypeptides were compatible with the levels of ST activities except that in female PP fraction the level of immunoreactive P-ST polypeptide was low in spite of comparatively high levels of P-ST activities. Chromatofocusing of PP and PV fractions separated P-ST activities into three major fractions (I-III), which have distinct catalytic and electrochemical properties. Fraction I was localized only in the PP samples in both sexes and revealed ST activities toward 2NAP at pH 5.5 and 7.4, while fraction II was localized in the PP and PV samples in both sexes with 2NAP-ST activity only at pH 7.4. Fraction III which had ST activities at pH 5.5 and 7.4 was present only in the PV samples in female rats, whereas in male rats it was present in both PP and PV samples. With anti-P-ST antiserum, the immunoreactive polypeptide was present in fraction III, but no immunoreactive band was detected in fractions I and II, suggesting the presence of immunochemically and electrochemically different P-ST(s) in these fractions.     

Chain Shuffling: Investigations into the Specificity and Selectivity of Antibody Catalysis

The antibody phage display system has been investigated as a vehicle for the potential altering of a catalytic antibody's specificity and chemical reactivity. Using previously identified catalytic antibodies, heavy and light “chain shuffling” experiments have been conducted. Catalytic activity and specificity requirements in terms of antibody complementarity-determining regions were probed by interchanging heavy and light chain genes between antibodies that catalyze class-similar but different chemical reactions with substrates that are enantiomerically opposed. The results were that antibody-hapten binding specificity was only slightly altered, but catalytic activity was severely compromised.     

Inhibitory long-term potentiation underlies auditory conditioning of goldfish escape behaviour

Long-term potentiation (LTP), the increase in synaptic strength evoked by high-frequency stimulation, is often considered to be a cellular model for learning and memory. The validity of this model depends on the assumptions that physiological stimuli can induce LTP in vivo and that the resulting synaptic modifications correlate with behavioural changes. However, modifiable synapses are generally embedded deep in complex circuits. In contrast, the goldfish Mauthner (M)-cell and its afferent synapses are easily accessible for electrophysiological studies, and firing of this neuron is sufficient to trigger fast escape behaviour in response to sudden stimuli. We have previously shown that tetanic stimulation can induce LTP of the feedforward inhibitory synapses that control the excitability of the M-cell. Here we report that natural sensory stimulation can induce potentiation of this inhibitory connection that resembles the LTP induced by afferent tetanization. Furthermore, comparable acoustic stimulation produced a parallel decrease in the probability of the sound-evoked escape reflex. Thus we demonstrate for the first time, to our knowledge, a behavioural role for the long-term synaptic strengthening of inhibitory synapses.     

Sensorless PM brushless DC motor drives

To control PM brushless DC motors, position and speed sensors are indispensable because the current should be controlled depending on the rotor position. However, these sensors are undesirable from standpoints of size, cost, maintenance, and reliability. There are different ways of approaching this problem, depending on the flux distribution. The paper presents the speed and position sensorless control of PM brushless DC motors with a sinusoidal flux distribution. Two approaches are presented and compared with each other; one is based on the voltage model of the motor and another is based on the current model. The starting procedure is also a very difficult problem under sensorless drives, because the sensorless drive algorithm uses voltage and current for estimation of rotor position, but no information is available before starting. A novel starting method is presented by using a salient-pole machine. Experimental results based on DSP-TMS320C25 controller are shown for comparisons, which demonstrate desired characteristics both in steady-state and starting conditions     

30-1000 MHz field strength standard developed in anechoic chamber

An accurate electric field strength for the frequency range of 30 MHz to 1000 MHz has been developed in a full anechoic chamber with 1-Σ uncertainty less than ±1.9%. Reflection parameters of walls at frequencies below 200 MHz are evaluated experimentally, and the errors due to these waves are compensated in the standard and calibrations of the antennas     

Vaporization study on the niobium monoxide and niobium metal systems by mass-spectrometric methods

The vapor pressures over single-phase NbO(s) and two-phase NbO(s) — Nb(s) were measured by the mass-spectrometric method in the temperature range 1948–2301 K. The main vapor species over both systems were observed to be NbO(g) and NbO₂(g). By applying the second and the third law treatments of thermodynamics to the partial vapor pressures of NbO(g) and NbO₂(g), the enthalpies of vaporization were calculated for the following reactions: NbO(inNbO(s)) = NbO(g), NbO₂(inNbO(s)) = NbO₂(g), 2NbO(s) = Nb(s) + NbO₂(g), 2NbO(s) = Nb(s)+NbO(g) + 0(g). The enthalpies of formation and the dissociation energies of NbO(g) and NbO₂(g) obtained from these reactions were in good agreement with the previous results obtained from the vapor pressure measurements on NbO₂(s) by the present authors. The partial pressures of oxygen were calculated as a function of temperature from the partial pressures of NbO₂(g) and NbO(g), from which the partial molar enthalpies and entropies of oxygen in the system of NbO(s) and Nb(s) were determined.     

Studies on suspension and emulsion. LIV. Shrinkage of polymer emulsion film having asymmetric porous structure

It was found that the film cast on a glass plate from emulsifier-free ethyl acrylate–methyl methacrylate copolymer emulsion when separated from there shrank and curled immediately. This film had an “asymmetric” porous structure. It was discussed the relationship between the porous structure and the shrinkage due to the residual internal stress produced during film formation.     

A case of interstitial pneumonia of polymyositis-dermatomyositis with various pathological findings in open lung biopsy

A 60-year-old woman was admitted to our hospital with a two month history of dry cough and dyspnea on exertion. A chest roentgenogram revealed diffuse interstitial shadows with a reduction of lower lung volume. Laboratory examinations revealed an increase in CPK and aldolase. There was decreased proximal muscle power, and the findings of a biopsy of the right deltoid were compatible with polymyositis. Myositic symptoms were stable, but the respiratory symptoms worsened, and an open lung biopsy was performed for diagnosis and to determine the best treatment. The histological findings of biopsy materials demonstrated active interstitial pneumonia complicated by cellular interstitial pneumonia, bronchiolitis obliterans organizing pneumonia, usual interstitial pneumonia and lymphoid hyperplasia. The patient responded well to adrenocorticosteroid and immunosuppressive therapy, and is now attending as an out patient. It is well known that PM-DM can be associated with interstitial pneumonia, and this complication is an important prognostic factor clinically. The pathological patterns of interstitial pneumonia in PM-DM may be divided into usual interstitial pneumonia and bronchiolitis obliterans organizing pneumonia. Furthermore, it is well documented that these patterns are concurrent with the response to adrenocorticosteroid and prognostic factors. However, our case of PM-DM, in which various patterns such as rheumatoid arthritis (RA) were pathologically revealed, cannot be considered as having uniform pathological pattern. We consider that pulmonary pathological patterns of PM-DM are very varied, as with RA. It is a very important to evaluate the nature of these patterns and the subsequent clinical course in PM-DM with interstitial pneumonia.