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BMC and BMD of the total body bone and lumbar spine were measured in normal control and patients with metabolic bone diseases by DPA (Dichromatic Bone Densitometer Model 2600, Norland corporation). Also, total body fat mass was measured in patients with obesity. We discussed basic technical problems and showed some data to assess patients with metabolic diseases known to affect the skeleton such as primary and secondary hyperparathyroidism. DPA is useful technique to assess patients with metabolic bone diseases and to monitor the efficacy of treatments.

We report two cases of Philadelphia (Ph1) chromosome positive acute mixed lineage leukemia (AMLL) with breakpoint cluster region (bcr) (M-BCR-1) rearrangement. A 31 year-old-man (case 1) and a 42 year-old-woman (case 2) were admitted to our hospital for further evaluation of leucocytosis with atypical blasts. Each case was diagnosed as having bilineal type of AMLL because: (1) blasts in each case consisted of larger myeloid cells positive for myeloperoxidase and small lymphoid cells positive for PAS, and blasts in case 2 were positive for TdT; (2) blasts in case 1 expressed B lymphoid associated antigen; (3) Southern analysis in each case showed clonal rearrangements of both the immunoglobulin heavy chain and the T cell receptor beta gene. These two cases demonstrated the Ph1 chromosome and rearrangement of the bcr (M-BCR-1) gene, but none of splenomegaly, basophilia, and additional chromosome abnormalities were observed. In addition, after achieving remissions, they didn't revert to chronic phase of chronic myelogenous leukemia (CML) and showed normal neutrophil alkaline phosphatase scores, and the Ph1 chromosome disappeared completely in case 1 and coexisted with the normal chromosome in case 2. These findings suggest that diagnosis of both cases should not be CML blast crisis (BC) but Ph1 positive acute leukemia, and Ph1 positive AMLL may be a distinct clinical entity to be distinguished from CML-BC.

The ultra high voltage transmission electron microscope (UHV-TEM) having an acceleration voltage of 1000 kV or more has been used for the observation of atomic structure of materials because of its high resolution approaching to 0.1 nm. Few effort has been done to develop an analytical UHV-TEM with energy dispersive x-ray spectroscope (EDS) for in-situ experiments such as ion irradiation, because high density of hard x-ray accompanied with primary electrons is supposed to prevent to measure the characteristic x-ray from the specimen. However, the observation of the heterostructures and interfaces requires analytical capability of determining the local chemical composition compatible with high resolution electron microscopy. This paper describes about a new analytical UHV-TEM (AHV-TEM) equipped with EDS and energy filtered imaging system and its application to Ni silicide thin film.The AHV-TEM in this study is based on JEM-ARM1000 with a side entry goniometer. Figure 1 shows the comparison of calculated CTF and optical diffractogram of amorphous Ge taken near Scherzer defocus with E=1000 keV, Cs=2.6 mm, Cc=3.4 mm and Qi=0.3 mrad.

Three Cylindrocladium species were isolated from Phellodendron amurense seedlings together with fungi belonging to 24 genera, and 11 genera from the tree roots. The three species were tested for pathogenicity on leaflets and seedlings of P. amurense. Cylindrocladium colhounii caused leaf blight and subsequent abscission of leaflets of seedlings, saplings, and trees, and damping-off of potted seedlings, but C. camellea and C. tenue were not pathogenic. The significance of Cylindrocladium species in relation to decline of P. amurense trees in Tokyo is discussed.

Seven days after subcutaneous injection of 2% carrageenin solution in mice, the induced inflammatory tissue was isolated and treated with 0.1% trypsin. When the dispersed cells were incubated in a nutrient medium containing 5--20% calf serum, the cells grew adhering to the culture-dish surface and colony-stimulating factor (CSF) was accumulated in the medium gradually. Addition of lipopolysaccharide (Escherichia coli endotoxin) in the cell culture did not enhance the CSF production. It was shown by isoelectrofocusing that the majority of the produced CSF was an acidic molecule (pI = 3.8), while the treatment of this CSF with neuraminidase yielded a less acidic CSF species (pI = 5.1). Upon gel-filtration chromatography in the presence of 6 M guanidine HCl, the CSF exhibited an apparent molecular weight of 42,000. On the other hand, polyacrylamide gel-electrophoresis in the presence of 0.1% sodium dodecyl sulfate gave a molecular weight estimate of 65,000. Microscopic examination of the bone marrow cell culture showed that about one-third of the colonies were granulocytic. Addition of prostaglandin E1(PGE1) in the bone marrow cell culture significantly inhibited the action of the CSF, while prostaglandin D2 was less inhibitory than PGE1. The result suggests that the cells isolated from the inflammatory tissue are capable of producing CSF, which may have a role for proliferation and maturation of the mononuclear phagocytes at the site of inflammation.

The Economic Load Dispatching (ELD) has been and is one of the key functions to be carried out in the Central Dispatching Office. Nowadays, owing to the increase of nuclear power plants, coal- & oil-fired power plants are asked to play a more important role in the ELD satisfying various operating constraints. This paper presents a unique algorithm for on-line ELD of 2-level scheme. The method, forecasting the total load demand P over one hour, handles changing the number of coal-mills & burners and output zone switching in terms of Advance-Dispatching-Time and Min-Zone-Time. The 2-level structure of the proposed ELD method is efficient computationally and is suited for on-line use. A more friendly procedure of the output zone switching is also tried using a small set of knowledge. The proposed method is being tested in the field aiming at the advanced automated operation in a utility.

1. The effects of alterations of the intracellular ionic composition on the properties of anomalous (or inward) rectification of the egg membrane of the starfish, Mediaster aequalis, were studied by using an intracellular perfusion technique. The following results were obtained, analysing the membrane current with the voltage-clamp technique. 2. The inward rectification of the K conductance depends only on the membrane potential, V, when the K equilibrium potential, VK, is altered by changing the internal K+ concentration at a fixed external K+ concentration, while it depends on V-VK when VK is altered by changing the external K+ at a fixed internal K+ concentration. 3. From the above the conclusion is reached that the gating of the K channel of the inward rectification depends on V and external but not internal K+ concentration. 4. The conductance of the K channel at a given voltage is roughly proportional to the square root of [K+]i when the latter is altered at a fixed external K+ concentration. 5. Since the conductance is proportional to the square root of [K+]o when this is altered at a fixed internal K+ concentration, the final conclusion is that this conductance is proportional to the geometric mean of the external and internal K+ concentrations. 6. Intracellular Na+ ions are necessary for the activation of inward rectification; the K conductance increases sharply with internal Na+ concentration, reaching saturation at 200 mM. 7. A similar potentiating effect is found for Li+, although it is weaker. Rb+, Cs+ and organic cations such as arginine+ do not have this effect.

A rotatory microcalorimeter of the conduction type has been designed for the study of microbial metabolic processes under both aerobic and anaerobic conditions. The instrument can be performed in either batch mode or flow mode by changing the calorimeter vessels and the tube connections. The sensitivity and the time constant were determined by electrical calibrations. The heat sensitivity was 0.12 mV/mW with both yeast and other fungi. Because of the sufficient aeration and agitation, the calorimeter is available for studies on the fungi growth experiments of biotechnical interest.

To obtain wider waveform equalization range and higher synchronization accuracy, we have introduced: 1) a multilevel pilot-pulse equalization system and 2)an in-band in-phase pilot synchronization system into multilevel VSB-conversion PCM-FDM equipment. This equipment is used to transmit digital signals on existing analog lines. 1) Multilevel pilot pulses with a smaller number of levels than the information pulses are inserted into the information pulse train. Due to the larger eye opening of the received pilot pulse, the automatic equalizer can converge and equalize the distortion more quickly and easily. For example, let 2-level pilot pulses be inserted into every 32 16-level information pulses. As long as the eye pattern of the pilot pulse is open, it is possible to allow up to 15 times more distortion in the transmission line. Thus the transmission span can be greatly extended. There are various other advantages in using this pilot pulse, such as dc drift suppression, in-service error rate monitoring, etc. 2) A carrier pilot and a sample timing pilot for phase synchronization are superimposed on the carrier frequency and 1/2 Nyquist rate, respectively, within the transmission signal spectra. Thus no excess bandwidth for pilots is necessary, and the phase error between pilot and signal is smaller. In this case, the phase jitter of regenerated carrier and timing clock caused by the neighboring signal spectra can decrease if the pilots are coupled in the same phase with the neighboring signal. For example, phase jitter of less than 0.5° (which was experimentally 1/10 phase error of the quadrature coupling) could be realized easily, even if the signal-to-pilot ratio is about 20 dB.

Monosynaptic excitatory connections between cerebellar granule and Purkinje cells were studied in dissociated cell cultures, and identification of the transmitter and the postsynaptic receptor at this synapse was pharmacologically investigated. The presynaptic granule cell and the postsynaptic Purkinje cell were voltage- or current-clamped simultaneously, and the excitatory postsynaptic current induced by the granule cell was examined. The neurons and monosynaptic excitatory connections were identified as in our earlier study. Several pairs of granule and Purkinje cells were stained with Lucifer yellow and propidium iodide, respectively, and their morphology was examined after electrophysiological recording. The monosynaptic excitatory postsynaptic current was suppressed by 1 mM kynurenate, an antagonist for excitatory-amino acid receptors, but was little affected by 0.2 mM DL-2-amino-5-phosphonovalerate, a selective antagonist of N-methyl-D-aspartate receptors. Glutamate and aspartate induced inward current in the Purkinje cells. These currents were suppressed by kynurenate at 1 mM. DL-2-Amino-5-phosphonovalerate at 0.2 mM suppressed the inward current induced by 100 microM aspartate but did not affect the inward current induced by 10 microM glutamate. These results are consistent with the idea that glutamate, or a glutamate-like substance, but not aspartate is the transmitter released at the synapse between granule and Purkinje cells and that non-N-methyl-D-aspartate receptor channels are functioning in the postsynaptic membrane.

A second generation LSI codec has been implemented. In this chip, switched-capacitor filters, a charge redistribution encoder and decoder, voltage references, a signaling logic circuit, and all necessary functions for voice-PCM conversion are integrated. The authors describe the codec and summarizes its characteristics.

1. The properties of the fast-inactivating or transient K current and the slowly inactivating or delayed K current of the membrane of immature eggs of the clonial marine coelenterate, Renilla Koellikeri, were studied by using voltage clamp and intracellular dialysis techniques. 2. The transient current is activated when the membrane potential becomes more positive than -25 approximately -20 mV (resting potential, -72 +/- 5 mV) whereas the activation potential of the delayed current is -10 approximately OmV. These potentials are independent of either [k+]o or [K+]i. 3. The inactivation of the transient current is rapid and is almost complete for membrane potentials more negative than the activation potential while it is slow for the delayed current and incomplete within a few seconds. 4. Both currents shows similar reversal potentials which are predominantly determined by the K concentration gradient across the membrane. 5. The sensitivities of the conductance upon the internal K concentration differ between the two currents, suggesting that the interaction between the site and ions in the membrane channels differ between them. 6. Neither current is a Ca-activated K current. 7. 4-AP suppresses the transient current at concentrations substantially smaller than those that suppress the delayed current while TEA shows no effect on either current. 8. Intracellular application of pronase or tannic acid at relatively high concentrations does not alter the inactivation of either current. 9. The membrane includes a voltage-dependent Ca permeability which results in action potentials under current-clamp conditions.

New thin film composite membrane system, designated PEC-1000, formed by the acid catalyzed polymerization on the surface of a reinforced-porous supporting membrane, make it possible to produce potable water from seawater by reverse osmosis in a single-stage with a high recovery operation. TDS rejection over 99.9% and stable water fluxes of 0.20–0.30 m3/m2-day (5.0–7.4 gal/ft2-day) have been attained with 3.5% synthetic seawater at an applied pressure of 56Kg/cm2(800psi). For brackish water, sodium chloride rejections of 99.6–99.9% and fluxes of 0.61–0.81m3/m2-day(15.0-20.0 gal/ft2-day) have been attained with 5000 ppm sodium chloride feed at an applied pressure of 40Kg/cm2 (571psi). TDS rejection of 99.8% and water flux of 0.30 m3/m2-day (7.4 gal/ft2-day) have been attained with two- or four-inch diameter PEC-1000 composite membrane elements at an applied pressure of 56Kg/cm2(800psi) in a single-stage synthetic seawater desalination test. This performance is kept for more than 1500 hours in PEC-1000 thin film composite membrane and two-inch diameter element. 280 ppm in TDS and water flux of 0.11 m3/m2 day (2.7 gal/ft2-day) are observed at an applied pressure of 56Kg/cm2-40% water recovery with one four-inch diameter spiral-wound PEC-1000 composite membrane element in a single-stage seawater desalination. This membrane shows high selectivity for low molecular weight valuable organic materials such as ϵ-caprolactam, dimethylsulfoxide, dimethylformamide. The thickness of ultrathin salt barrier of the composite membrane is found to be 300A by the Electron Microscopy with special ultrathin section techniques.

Using the whole-cell variation of the patch-clamp technique, we have found a voltage-dependent K+ current in human natural killer (NK) cells. This K+ current is reduced in a dose-dependent manner by a variety of ion-channel blockers (verapamil, quinidine, 4-aminopyridine, Cd2+) at concentrations comparable to those that inhibit natural killing. Pretreatment of target cells with quinidine or verapamil did not significantly reduce their sensitivity to killing, whereas substantial inhibition of killing was observed after pretreatment of effector cells. Both verapamil and quinidine reduced the proportion of effector-target cell conjugates, suggesting that K channels play a role in the "binding" phase of the killing process. By adding EDTA or channel blockers as various times in a Ca-pulse assay system, we have also delineated a blocker-sensitive phase of bound conjugates that strictly corresponds with the Ca-dependent "programming" stage of killing. In contrast, the killer cell-independent stage, which is Ca2+ independent, apparently does not require functioning K channels. Verapamil and quinidine do not affect target cell sensitivity to the putative soluble mediator of natural killing, natural killer cytotoxic factor (NKCF), but inhibit release of NKCF from NK cells. Thus, the data suggest that K channels in NK cells play essential roles in the natural killing process that include events in the "programming-for-lysis" phase leading to release of NKCF.

前報に引続いてカーボンブラックのヨウ素吸着について考察を行なった. ヨウ素吸着量と電子顕微鏡表面積及び窒素吸着表面積を比較することによって, ヨウ素分子1個の吸着断面積はほぼ40A2であることがわかる. したがってヨウ素吸着量から推定される表面積は外部表面積のみを表わし, 表面の微細孔に基づく内部表面積には関係しないことがわかる. またカーボンブラック表面に存在するタール状物質をベンゼン抽出によって除去すると吸着量と吸着熱が変化することを見出し, この事実と原料油の性質との関係について考察した. さらに真空脱気の影響と簡便測定法を検討した. 後者について, 正しい測定を行なうための最も重要な要因はヨウ素とヨウ化の比率を正しく一定にすることである.

1. The ionic mechanism of the action potential produced in lamella-like muscle cells of amphioxus, Branchiostoma californiense, was investigated with intracellular recording and polarization techniques. 2. The resting potential and action potential overshoot in normal saline are −53±5 mV ( S.D.) and +29±10 mV ( S.D.) respectively. 3. The action potential is eliminated by tetrodotoxin (3 μ M) and by replacing NaCl in the saline with Tris-chloride but maintained by replacing Na with Li. 4. After elimination of the normal action potential by tetrodotoxin or replacing Na with Tris, the addition of procaine (7·3 m M) to the external saline makes the membrane capable of producing a regenerative potential change. 5. The peak potential of the regenerative response depends on external Ca concentration in a manner predicted by the Nernst equation with Ca concentrations close to normal. 6. The Ca dependent response is reversibly suppressed by Co or La ions. 7. Similar regenerative responses are obtained when Ca is substituted with Sr or Ba. 8. It is concluded that two independent mechanisms of ionic permeability increase occur in the membrane of amphioxus muscle cell, one to Na and the other to Ca.

Five heterologous phages carry out the 0–1 conversion but differ from each other in host ranges and serological properties. To explain the origin of this class of phages, the hypothesis of a phage-to-phage transfer of conversion gene(s) mediated by a third phage has been proposed and tested experimentally, using Salmonella anatum and its phages ϵ 15 c and g 341 as a model system. Phage lysates prepared from mixedly infected cells proved to contain, besides parental phages, particles that carry one phage genome wrapped with head and tail proteins of another phage in reciprocal combination. The results are in agreement with the hypothesis.

UV induction of cells A(ϵ15, ϵ34) resulted in formation of two types of hybrid phage (hybrid I and hybrid II) in regard to O-antigen conversion properties, each being capable of inducing synthesis of both O-antigens 15 and 34. Hybrid I carries genetic material consisting mainly of phage ϵ15 genome, into which O-34 conversion genes of phage ϵ34 are incorporated. Its ϵ15 genome has been shown to be of ϵ15b type by genetic recombination experiments between the hybrid and conversion mutants ϵ15a or ϵ15b. Hybrid II (= II-6) carries mainly phage ϵ34 genome, into which O-15 conversion genes of phage ϵ15 are incorporated. It carries a complete set of O-34 conversion genes since double lysogens, A(II-6, ϵ15a) and A(II-6, ϵ15b), show complete O-antigens 34. It carries an incomplete set of O-15 conversion genes since (1) it is unable to synthesize complete O-15, (2) genetic complementation occurs between II-6 and ϵ15a or between II-6 and ϵ15b in regard to the synthesis of O-15 and (3) wild-type ϵ15 is produced by crosses between II-6 and ϵ15a or between II-6 and ϵ15b, although it is not possible to decide whether O-15 conversion genes of II-6 is of ϵ15a type or of ϵ15b type. The significance of these findings is discussed.

Salmonella anatum 1 (=A1株とする) -O抗原構造3.10-をe15ファージで溶原化し, A1(e15)-O抗原3.15-を得た。 A1(e15) 株の培養にe34vir hファージを加えてO抗原3.15の細胞を殺してしまうと, 約10-5 (8.4×10-6) の割合に生残り細胞を認め, その中R型細胞が6.3×10-6, S型細胞が2.13×10-6の割であつた。 S型細胞 (2.13×10-6) の中1.66×10-6は “O抗原3.10, e15及びC341ファージに感性, e34 vir及びe34 vir hファージに抵抗性で, 且e15で溶原化するとO抗原が3.10から3.15に変換する” という点も含め, 諸性状がA1と同一であり, 従つて自然にプロファージe15を失つた細胞と考えられる。 O抗原3.15の菌株を抗15因子血清加培地に培養すると, O抗原3.10の細胞が得られる (小原, 1950; 中川 (武), 1953; Uetake, et al., 1955) のは, このプロファージを自然に失つた細胞を把握しているものと考えられる。尚S型細胞の中にはe16b (e15の突然変異株: Uetake, et al., 1959) をもつ細胞 (4.1×10-7) も含まれていた。

When phage e 34 infects bacteria of group E 2 (lysogenic for phage e 15 , O antigens 3,15) it converts them to group E 3 (O antigens (3)(15)34). Salmonella anatum , belonging to group E 1 (O antigens 3,10) was lysogenized with phage e 34 . The strainsA( e 34 ) resemble S. anatum in O antigens and in sensitivity to various phages, except phage C 341 . When cells A( e 34 ) are infected or lysogenized with phage e 15 , both antigens 15 and 34 are synthesized. The formation of antigen 34 is always associated with the formation of a form of antigen 15 less complex in structure than the antigen 15 in A( e 15 ). This cooperation between phages e 15 and e 34 in the synthesis of antigen 34 indicates that the presence of the machinery for the synthesis of antigen 15 is a necessary prerequisite for the formation of antigen 34.

The membrane potential and conductance of the giant muscle fiber of a barnacle (Balanus nubilus Darwin) were analyzed in relation to changes in the external (3.5–10.0) and the internal (4.7–9.6) pH, under various experimental conditions. A sharp increase in membrane conductance, associated with a large increase in conductance to Cl ions, was observed when the external pH was lowered to values below 5.0. The ratio of Cl to K conductance in normal barnacle saline is between ⅙–1/7 at pH 7.7, whereas at pH 4.0 the ratio is about 6–9. The behavior of the membrane in response to pH changes in a Cl-depleted muscle fiber shows that the K conductance decreases with decreasing external pH for the whole range of pH examined. A steep increase in Cl conductance is also observed when the internal pH of the fiber is lowered below 5.0. The K to Cl conductance ratio increases with increasing internal pH in a manner very similar to that found when the external pH is raised above 5.0. These facts suggest that the membrane is amphoteric with positive and negative fixed charge groups having dissociation constants such that at pH greater than 5, negative groups predominate and cations permeate more easily than anions, while at lower pH positive groups predominate, facilitating the passage of anions through the membrane.

Recordings have been analysed of the songs of five different species of Japanese cicadas: Graptopsaltria nigrofuscata Mots., Oncotympana maculaticollis Mots., Tanna japonensis Dist., Meimuna opalifera Walk., and Platypleura kaempferi F. The song was always composed of pulses of sound (damped oscillations) which are produced repetitively at a frequency of 200–500/sec by the contraction of the main sound muscle. Rhythmical changes occur in the amplitude and shape of the sound pulses. The frequency spectrum of sound shows a marked overlapping among the songs of different species but the rhythm in amplitude or shape of the pulses is specific for the species of cicada. It is concluded that species discrimination in cicadas is accomplished by discriminating the differences in these rhythms.

Salmonella phages g341 and ϵ15 have in common the genetic function that upon lysogenization they repress transacetylation to galactose residues of lipopolysaccharide side chains of the host bacterial cells. Recombinant phages were isolated from lysates prepared either by inducing double lysogens carrying prophages g341 and ϵ15a, a mutant of ϵ15 lacking the repressing function, or by mixed infection of sensitive cells with both phages. These phages are not related to each other in various properties, including plaque morphology, host range, immunity specificity, and serological property. Similar hybrid phages were also isolated from lysates prepared by mixed infection with ϵ15a and C341, a clear-plaque mutant of g341.

種々のカーボシブラックのヨウ素吸着をヨウ素一ヨウ化カリ水溶液を用いて測定した. 吸着速度は比較的早く15分でほぼ平衡に達する. 吸着恒温曲線から先ず単分子層が形成され次に多公子層吸着に移行して行くことがわかる. この吸着恒温曲線は Langmuir の吸着式には従わず, BET式に従う. 吸着前後において溶液中のヨウ素イオン濃度が変化し, その状態はカーボンブラックの種類によって異なるが, ヨウ素イオンの減少はイオンの吸着に基づくものであり, イオンの増加はヨウ素分子の還元に基づくものである. 吸着と脱着のヒステレシスはほとんど認められず, カーボンブラックのヨウ素吸着は物理吸着と考えることができる.

The fine structure near electron harmonic resonances was observed in the radiation from a magnetoplasma. It is explaine by takin account of electron temperature and spatial distribution of electron density. The explanation is based upon Bernstein's dispersion relation modified by employing a distribution function. The mechanism of the fine structure is the same as one Buchsbaum, Hasegawa mentioned.

Electrical properties of the cell membrane were studied in the neoplastic lymphocyte, mouse myeloma cell line S194, by using the whole-cell patch clamp technique. Inward Ca2+ currents due to voltage-gated Ca2+ channels were found. The current, which decayed exponentially after reaching a peak, was first activated at about -50 mV and attained its maximum peak amplitude at about -20 mV in a 10 mM Ca2+ solution. Outward current was negligible for the potential range more negative than +30 mV. The channel was permeable to Sr2+ and Ba2+ in addition to Ca2+. Among these species, Sr2+ carried the greatest current. The time constants of the decay of the current depended neither on the species nor on the concentration of charge carrier. The steady-state inactivation was observed at potentials more negative than those at which the inward Ca2+ current was activated. Thus, we concluded that the inactivation of the channel was mainly voltage dependent. For reasons that are not yet understood, the amplitude of the Ca2+ current varied greatly among cells.

1. The blocking effects of Ba+ and H+ on the inward K current during anomalous rectification of the giant egg membrane of the starfish, Mediaster aequalis, were studied using voltage clamp techniques. 2. External Ba2+ at a low concentration (10--100 micron) suppresses the inward K current; the extent of suppression, expressed as the ratio of currents with and without Ba2+, can be described by a conventional bimolecular adsorption isotherm, K/(K + [Ba2+]o), K being an apparent dissociation constant. 3. The dissociation constant, K, decreases as the membrane potential V becomes more negative and can be expressed by K(V) = K(0) exp (zmuFV/RT), where K(0) is the K at V = 0, z is the charge of the blocking ion, and mu is a parameter for the membrane potential dependence of Ba2+ blockage. The value of mu ranges between 0.64 and 0.68. 4. Upon a sudden change in membrane potential the change in the blocking effect of Ba2+ follows first order kinetics; the forward rate constant is membrane-potential-dependent whereas the backward constant is potential-independent. 5. The blocking effect of Ba2+ appears to be independent of the activation of K channels during anomalous rectification. 6. The blocking effect of Ba2+ depends on V alone, in contrast to the activation of the K channel during anomalous rectification which depends on V--VK. 7. In these respects, the effect of Ba2+ is equivalent to the introduction of inactivation into the anomalous rectification. 8. SI2+ and Ca2+ show small but observable blocking effects only at much higher concentrations (about 10--20 mM). 9. The inward K current is suppressed when the external pH is reduced below 6.0. The blocking effect of H+ shows no significant potential dependence. The concentration dependence suggests that three H+ ions simultaneously titrate the acidic groups of each channel (pK = 5.3--5.4). 10. The implications of these results are discussed in terms of molecular models of the potassium channel of anomalous rectification and possible mechanisms of K channel inactivation.