Cardiac malignant pheochromocytoma with bone metastases.

A patient with malignant cardiac pheochromocytoma with bone metastases is described. The primary tumor was located between the pulmonary trunk and the left atrium, while metastatic lesions were found in the iliac bones. Treatments with antihypertensive agents, alpha-methylparatyrosine, and combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine partially improved the patient's symptoms, catecholamine levels, and the metastatic lesion of the iliac bones.

[Hemolytic uremic syndrome after bone marrow transplantation].

One hundred and thirteen patients who underwent autologous or allogeneic bone marrow transplantation (BMT) were investigated for the subsequent development of hemolytic uremic syndrome (HUS). HUS developed in seven patients (four males and three females, five acute lymphocytic leukemia (ALL), one acute myelogenous leukemia, one non-Hodgkin's lymphoma) between 36-196 days after BMT. Four patients were recipients of autologous BMT and three were those of allogeneic BMT.

AMPA receptor desensitization modulates synaptic responses induced by repetitive afferent stimulation in hippocampal slices.

In patches excised from CA1 pyramidal cells, peak amplitudes of currents evoked by brief glutamate pulses grew progressively smaller over a series of high-frequency pulses. This decline was eliminated by cyclothiazide, a drug previously shown to block AMPA receptor desensitization. In hippocampal slices, synaptically evoked bursts exhibited an increase from the first to the second response, presumably due to facilitation of transmitter release, but the subsequent responses gradually declined in amplitude.

The waveform of synaptic transmission at hippocampal synapses is not determined by AMPA receptor desensitization.

Relationships between the kinetic properties of AMPA receptors and the decay phase of fast excitatory transmission were investigated using modulatory drugs. The benzothiadiazide compound cyclothiazide blocked receptor desensitization in patches excised from hippocampus but had only a weak influence on receptor deactivation, i.e.

Lyn physically associates with the erythropoietin receptor and may play a role in activation of the Stat5 pathway.

Protein tyrosine phosphorylation plays a crucial role in signaling from the receptor for erythropoietin (Epo), although the Epo receptor (EpoR) lacks the tyrosine kinase domain. We have previously shown that the Jak2 tyrosine kinase couples with the EpoR to transduce a growth signal. In the present study, we demonstrate that Lyn, a Src family tyrosine kinase, physically associates with the EpoR in Epo-dependent hematopoietic cell lines, 32D/EpoR-Wt and F36E.

Molecular cloning and nucleotide sequence of the pyruvate kinase gene of an actinomycete Microbispora thermodiastatica.

The gene for the thermostable pyruvate kinase of Microbispora thermodiastatica IFO 14046, a moderate thermophilic actinomycete, was cloned in Escherichia coli. This gene consists of an open reading frame of 1422 nucleotides and encodes a protein of 474 amino acids with molecular mass of 50,805 Da. The open reading frame was confirmed as the pyruvate kinase gene by comparison with the N-terminal amino acid sequence of the purified pyruvate kinase from M.

Arrangement of actin filaments and cytoplasmic granules in the sea urchin egg after TPA treatment.

Elongation of microvilli and formation of actin filaments after treatment with a phorbol ester, TPA, were investigated in unfertilized eggs of Hemicentrotus pulcherrimus. Microvilli on the egg surface were examined by scanning electron microscopy. Actin filaments in the cortical layer of the eggs were observed by fluorescence microscopy using rhodamine-labeled phalloidin.

Cerebellar ataxia and peripheral neuropathy due to chronic bromvalerylurea poisoning.

A patient with chronic bromvalerylurea poisoning showed cerebellar ataxia and peripheral neuropathy. The patient was a 42-year-old Japanese man who developed consciousness disturbance, diplopia, slurred speech, ataxia and gait disturbance after having taken bromvalerylurea for ten years. Magnetic resonance imaging revealed atrophy of the cerebellum and pontine tegmentum.

Murine cardiac progenitor cells require visceral embryonic endoderm and primitive streak for terminal differentiation.

Cardiac progenitor cells in avian and amphibian embryos are known to commit to cardiac lineage during gastrulation or early neurulation. These cells require cell interaction with anterior endoderm for their differentiation into cardiomyocytes. However, little is known about cell interaction in mammalian cardiogenesis.

Erythropoietin and IL-3 induce tyrosine phosphorylation of CrkL and its association with Shc, SHP-2, and Cbl in hematopoietic cells.

The present study demonstrates that erythropoietin (Epo) and IL-3 induce tyrosine phosphorylation of the SH2/SH3-containing adapter protein CrkL and its transient association with tyrosine-phosphorylated SHP-2, Shc, and Cbl in a murine IL-3-dependent cell line, 32D, expressing the Epo receptor (EpoR). In these cells, CrkL was constitutively complexed with the guanine nucleotide exchange factor C3G, which was found to coimmunoprecipitate with Shc from Epo- or IL-3-stimulated cells. Studies using cells expressing mutant EpoRs showed that the Epo-induced tyrosine phosphorylation of CrkL is dependent on the membrane-proximal EpoR cytoplasmic region involved in the activation of Jak2 as well as the C-terminal 145 amino acid region which is required for tyrosine phosphorylation of SHP-2 and Shc.

A profile of the behavioral changes produced by facilitation of AMPA-type glutamate receptors.

A newly developed group of benzoylpiperidine drugs that enhance AMPA-receptor-gated currents ("ampakines") has been shown to improve memory encoding in rats across a variety of experimental paradigms. The present experiments were intended to i) provide a partial profile of the behavioral changes produced by ampakines, ii) test if two ampakines (BDP-12 and BDP-20) that differ significantly in their effects on AMPA receptor kinetics produce similar behavioral profiles, and iii) determine if physiological potency is reflected in behavioral potency. BDP-20 reduced two measures of exploratory activity in aged rats but increased speed of performance in a radial maze; the drug also caused substantially improved retention of spatial information.

Using cardiac phase to order reconstruction (CAPTOR): a method to improve diastolic images.

A method is proposed to reconstruct multiphase images that accurately depicts the entire cardiac cycle. A segmented, gradient-recalled-echo sequence (FASTCARD) was modified to acquire data continuously. Images were reconstructed retrospectively by selecting views from each heartbeat based on cardiac phase rather than the time elapsed from the QRS complex.

Stable expression of recombinant AMPA receptor subunits: binding affinities and effects of allosteric modulators.

Homomeric AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)-type glutamate receptors (GluRs) were stably expressed in kidney cells from cDNAs encoding GluR1 flop, GluR2 flip, GluR2 flop, and GluR3 flop subunits. The recombinant receptors were of the expected size and showed functional properties in whole-cell recording as previously reported. [3H]AMPA binding to all subunits was increased to a similar extent by the chaotropic ion thiocyanate (SCN-).

Maximum oxidative phosphorylation capacity of the mammalian heart.

It is difficult to estimate the maximum in vivo aerobic ATP production rate of the intact heart independent of limitations imposed by blood flow, oxygen delivery, and maximum mechanical power. This value is critical for establishing the kinetic parameters that control oxidative phosphorylation, as well as for providing insights into the limits of myocardial performance. In this study, the maximum ADP-P(i)-driven heart mitochondrial respiratory rate (MV(O2 mito)) was determined with saturating levels of oxygen, substrates, and cofactors at 37 degrees C.

cDNA cloning, expression and chromosome mapping of the human STAT4 gene: both STAT4 and STAT1 genes are mapped to 2q32.2-->q32.3.

Studies of transcriptional activation by interferons and a variety of cytokines have led to the identification of a family of proteins that serve as signal transducers and activators of transcription (STAT). STAT4 is phosphorylated following interleukin (IL)-12 stimulation and is essential for IL-12 signal transduction. The human STAT4 cDNA was cloned, and both STAT4 and STAT1 genes were mapped to human chromosome bands 2q32.

Purification and characterization of a thermostable pyruvate kinase from the actinomycete Microbispora thermodiastatica.

The pyruvate kinase of Microbispora thermodiastatica was purified to homogeneity and some properties of the enzyme were characterized. The molecular weight of the enzyme by gel filtration is 277,000. The subunit molecular weight is 55,000 by SDS-polyacrylamide gel electrophoresis, and only one N-terminal amino acid sequence was obtained.

Effects of a centrally active benzoylpyrrolidine drug on AMPA receptor kinetics.

A newly developed benzoylpyrrolidine drug (BDP-20) that increases the size of fast, excitatory synaptic responses was examined for its effects on the kinetic properties of alpha-amino-3-hydroxy-5-methyl-4-isoxalepropionic acid (AMPA)-type glutamate receptors. When long pulses of glutamate were applied to excised hippocampal patches of the rat, the compound BDP-20 caused an approximately 15-fold reduction in the rate at which responses desensitized and a similar size increase in steady-state currents. In experiments using 1-ms glutamate pulses, BDP-20 prolonged response deactivation by a factor of about four and greatly reduced the depression in the second response when two consecutive glutamate pulses were given.

Effect of the AMPA receptor modulator IDRA 21 on LTP in hippocampal slices.

IDRA 21 (7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine S,S-dioxide) has been reported to modulate AMPA receptor kinetics and to improve memory in certain animal models. In the present study, its effects on synaptic transmission and long-term potentiation (LTP) were tested in hippocampal slices. IDRA 21 (500 microM) significantly increased the amplitude and halfwidth of field EPSPs.

Effects of a memory-enhancing drug on DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor currents and synaptic transmission in hippocampus.

The benzoylpiperidine drug BDP-12 (1-(quinoxalin-6-ylcarbonyl)piperidine) enhances the encoding of transient and stable forms of memory by rats. Results reported here show that the drug increases fast, excitatory (glutamatergic) synaptic responses in hippocampal slices by about 50% with an EC50 of 170 microM. Analyses with polysynaptic responses indicated that the drug has a facilitatory action at concentrations as low as 12.

Spectroscopic determination of cytochrome c oxidase content in tissues containing myoglobin or hemoglobin.

A simple spectroscopic method for determining the cytochrome c oxidase, cytochrome a, a3, content in tissue and mitochondria samples independent of myoglobin or blood contamination is described. Using tissue homogenates solubilized in Triton X-100, this assay relies on the selective reduction of mitochondrial cytochromes by the action of potassium cyanide. Monitoring the optical absorbance of these samples at 605 nm provided a quantitative determination of cytochrome c oxidase content in the presence of myoglobin or blood.

Roles of Cl- channels and Ca2+ mobilization in stretch-induced increase of SA node pacemaker activity.

Ionic mechanisms underlying the enhancement of cardiac pacemaking activity by mechanical stretch were investigated in the isolated rabbit sinoatrial (SA) node. A 5-s stretch of 0.2-2.

Response to repetitive stimulation of AMPA receptors in patches excised from fields CA1 and CA3 of the hippocampus.

Patches excised from fields CA1 and CA3 of the hippocampus were used to study AMPA receptor responses to repetitive application of brief pulses of agonist. AMPA receptors in field CA1 exhibited a larger degree of paired-pulse depression and a slower recovery rate from desensitization than those from CA3 patches. Responses became progressively smaller during a train of short pulses (4 at 100 Hz), an effect that was greater in CA1 than CA3 patches and that was blocked by a drug (cyclothiazide) that slows desensitization.

Effect of cyclothiazide on binding properties of AMPA-type glutamate receptors: lack of competition between cyclothiazide and GYKI 52466.

The effects of cyclothiazide on the properties of (R,S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors were studied using equilibrium binding techniques and interactions with other compounds known to modulate the receptors. Cyclothiazide caused a reduction in [3H]AMPA binding in assays carried out in the presence of thiocyanate, a chaotropic ion that markedly increases the affinity of AMPA receptors and accelerates their desensitization. In the absence of thiocyanate, however, cyclothiazide had no reliable effect on the binding of [3H]AMPA or on the affinity for this agonist assessed from the displacement of [3H]CNQX.

Differences in the refractory properties of two distinct inhibitory circuitries in field CA1 of the hippocampus.

Extracellular reflections of IPSPs were examined in two distinct circuitries in field CA1 of the hippocampus. Stimulation in the stratum radiatum in the presence of AMPA receptor antagonists elicited positive potentials in the same stratum that were eliminated by picrotoxin, a blocker of GABAA receptors. Laminar profile analysis revealed that the response was maximal in the stratum radiatum at a point well distal to the pyramidal cell body layer and had a negative reflection in the stratum oriens.