The effect of pretreatment with a delta 2-opioid receptor antisense oligodeoxynucleotide on the recovery from acute antinociceptive tolerance to delta 2-opioid receptor agonist in the mouse spinal cord

1. An intrathecal (i.t.) injection of a selective delta 2-opioid receptor agonist, [D-Ala2]deltorphin II, produced an acute antinociceptive tolerance to the antinociceptive effect of a subsequent i.t. challenge of [D-Ala2]deltorphin II. This acute tolerance lasted 3 to 9 h and completely subsided by 12 h. The experiments were designed to examine the effect of pretreatment with an antisense oligodeoxynucleotide to delta 2-opioid receptor mRNA (delta-AS oligo) on the recovery from tolerance to [D-Ala2]deltorphin II-induced antinociception in male ICR mice. 2. Pretreatment with delta-AS oligo (1.63 to 163 pmol, i.t.), but not mismatched oligo (MM oligo) (163 pmol), prevented the recovery from acute tolerance to [D-Ala2]deltorphin II-induced antinociception in a dose-dependent manner. However, treatment with delta-AS oligo (163 pmol) did not prevent the recovery from tolerance to either the mu-opioid receptor agonist [D-Ala2,NMePhe4,Gly(ol)5]enkephalin (DAMGO) or the kappa-opioid receptor agonist U50,488H, indicating subtype specificity in the mechanism by which delta-AS oligo inhibits recovery from delta 2-opioid tolerance. 3. Treatment with [D-Ala2]deltorphin II (i.t.) significantly reduced the binding of [tyrosyl-3,5-(3)H(N)]-Tyr-D-Ser-Gly-Phe-Leu-Thr ([3H]-DSLET), a delta 2-opioid receptor agonist ligand, in the spinal cord 3 h after treatment, but binding returned to control levels by 24 h after treatment. However, [3H]-DSLET binding in the spinal cord remained significantly reduced at 24 h if delta-AS oligo (163 pmol) was coadministered with [D-Ala2]deltorphin II (6.4 nmol). 4. Based on these findings, it is concluded that a single stimulation of spinal cord delta 2-opioid receptors by intrathecally-administered [D-Ala2]deltorphin II induces a long-lasting desensitization of delta 2-opioid receptors to [D-Ala2]deltorphin II. Recovery from delta 2-opioid receptor-mediated antinociceptive tolerance apparently depends on replenishment by newly synthesized delta 2-opioid receptor protein rather than immediate reversal of delta 2-opioid receptors.

[Comparison of long-term survival between bone marrow transplantation and maintenance chemotherapy for adult acute lymphoblastic leukemia in first remission]

To clarify the efficacy of allogeneic bone marrow transplantation (BMT) for adult ALL in first remission we retrospectively studied long-term outcomes of adult ALL patients of age between 15 and 44 years who were treated in our institute from 1980 to 1990. In this period thirteen patients with HLA compatible donors were offered allogeneic BMT during the first remission, while 16 patients without HLA-compatible donor were treated with maintenance chemotherapy (Cancer Chemoth Pharmacology 33:359-365, 1994). Patient and disease characteristics (age, leukocyte count at presentation, immunophenotype, Ph1 chromosome, and duration to first remission) in the two groups were not significantly different (chi-square test p > 0.1). As causes of treatment failure, relapse was 90% for chemotherapy while relapse and therapy-related death were 67% and 33%, respectively, for transplantation. The leukemia-free survival (LFS) rates at 10 years were 52 +/- 13% for transplantation and 30 +/- 11% for chemotherapy (P > 0.2, g-Wilcoxon, Logrank). The 10-year-LFS rates of Ph1-negative patients of 15 to 29 year-old were 67 +/- 15% for transplantation (n = 9) and 62 +/- 15% for chemotherapy (n = 8) (P > 0.9). Although the present data are derived from a non randomized retrospective study and a relatively small number of patients, this study revealed no superiority of BMT over chemotherapy for the prolongation of first remission in adult ALL, especially, in a standard risk group such as young patients without Ph1 chromosome.

Delta-1 opioid receptor-mediated antinociceptive properties of a nonpeptidic delta opioid receptor agonist, (-)TAN-67, in the mouse spinal cord

The effects of enantiomorphs of TAN-67 (2-methyl-4a alpha-(3-hydroxyphenyl)-1,2,3,4,4a,5,12,12a alpha-octahydro-quinolino[2,3,3-g]isoquinoline), (-)TAN-67 and (+)TAN-67, given intrathecally (i.t.) on antinociceptive response with the tail-flick test were studied in male ICR mice. (-)TAN-67 at doses from 17.9 to 89.4 nmol given i.t. produced a dose- and time-dependent inhibition of the tail-flick response, whereas its enantiomer (+)TAN-67 even at smaller doses (1.8, 4.5 and 8.9 nmol) given i.t. decreased the latencies of the tail-flick response. In addition, (+)TAN-67 at higher doses (17.9-89.4 nmol) given i.t. produced scratching and biting pain-like responses. The antinociceptive response induced by i.t.-administered (-)TAN-67 was mediated by the stimulation of delta-1 but not by delta-2, mu or kappa opioid receptors, because the effect was blocked by the i.t. pretreatment with BNTX, but not by naltriben, [D-Phe-Cys-Tyr-[D-Try-Orn-Thr-Pen-Thr-NH2 or nor-binaltorphimine dihydrochloride. Pretreatment with (-)TAN-67 given i.t. 3 hr earlier attenuated the tail-flick inhibition induced by subsequent i.t. administration of (-)TAN-67 and by [D-Pen2,5]enkephalin (DPDPE). However, the tail-flick inhibition induced by [D-Ala2]deltorphin II, [D-Ala2,NMePhe4,Gly5-ol]enkephalin and U50,488H were not affected by (-)TAN-67 pretreatment. Conversely, pretreatment with DPDPE given i.t. 3 hr earlier attenuated the tail-flick inhibition induced by subsequent i.t. administration of (-)TAN-67 and by DPDPE. However, the tail-flick inhibition induced by [D-Ala2]deltorphin II was not affected by i.t. DPDPE pretreatment. It is concluded that (-)TAN-67 given i.t. produces delta-1 opioid receptor-mediated antinociception; on the other hand, its enantiomer (+)TAN-67 produces hyperalgesia. Present studies provide other evidence that delta-1 opioid receptors exist separated from delta-2 opioid receptor.

High signal intensity on T2-weighted magnetic resonance imaging and cerebral hemodynamic reserve in carotid occlusive disease

BACKGROUND AND PURPOSE

The importance of MR imaging in carotid artery disease is unclear. We evaluated the sensitivity and specificity of the high signal intensity changes on MR images for diagnosis of hemodynamically compromised unilateral internal carotid artery disease.

METHODS

We evaluated the association of high signal intensities on T2-weighted MR images with changes in cerebral perfusion reserve measured using 99mTc-hexamethylpropyleneamine oxime single-photon emission CT and acetazolamide in 23 patients.

RESULTS

Eleven patients had a type I response (normal flow and normal perfusion reserve), 8 patients had a type II response (normal flow and decreased perfusion reserve), and 4 patients had a type III response (decreased flow and decreased perfusion reserve). High signal intensities in the centrum semiovale (11/12) and/or posterior periventricular white matter (6/12) were frequently seen in the hemodynamically compromised groups. Extensive high signal intensities were associated with severely impaired cerebral circulation. MR imaging had high sensitivity (0.92) and specificity (1.0) in predicting hemodynamically compromised patients when we used the presence of T2 high intensity in the centrum semiovale as a criterion.

CONCLUSIONS

The centrum semiovale T2 hyperintensities lateralized to the side of carotid occlusion are specific and sensitive for the presence and severity of hemodynamic compromise from carotid occlusive disease.

Antisense oligodeoxynucleotide to delta opioid receptors blocks cocaine-induced place preference in mice

The effect of intracerebroventricular (i.c.v.) treatment with antisense oligodeoxynucleotide (A-oligo) to delta opioid receptor mRNA on cocaine-induced place preference was examined in mice. Cocaine (10 mg/kg, s.c.) produced a significant place preference. I.c.v. treatment with A-oligo (0.001-1 microg/mouse) dose-dependently attenuated the cocaine (10 mg/kg, s.c.)-induced place preference, although mismatched oligodeoxynucleotide (1 microg/mouse, i.c.v.) was ineffective. In the present study, we found that the selective reduction in number and/or function of central delta opioid receptors by A-oligo suppresses the cocaine-induced place preference. These results suggest that the conditioned reward by cocaine may be partially mediated by central delta opioid receptors.

Pretreatment with protein kinase C activator phorbol 12,13-dibutyrate attenuates the antinociception induced by mu- but not epsilon-opioid receptor agonist in the mouse

The effects of pretreatment with a protein kinase C activator, phorbol 12,13-dibutyrate, on antinociception induced by i.c.v.-administered mu-opioid receptor agonist (D-Ala2, NMePhe4, Gly(ol)5) enkephalin (DAMGO) or morphine and epsilon-opioid receptor agonist beta-endorphin were studied in male ICR mice. The tail-flick responses were used for antinociceptive tests. I.c.v. pretreatment with phorbol 12,13-dibutyrate (50 pmol) for 30 or 60 but not 10 min attenuated antinociception induced by i.c.v.-administered DAMGO. I.c.v. pretreatment with phorbol 12,13-dibutyrate (10 and 50 pmol) for 60 min caused a dose-dependent attenuation of DAMGO (19.5 pmol)- or morphine (6.0 nmol)-induced antinociception. The dose-response curve for DAMGO-induced antinociception was shifted to the right by 7.3-fold by i.c.v. pretreatment with phorbol 12,13-dibutyrate (50 pmol) for 60 min. However, the i.c.v.-administered beta-endorphin-induced antinociception was not affected by the same pretreatment with phorbol 12,13-dibutyrate. The attenuation of i.c.v.-administered DAMGO- and morphine-induced antinociception by phorbol 12,13-dibutyrate was reversed by concomitant i.c.v. pretreatment with a selective protein kinase C inhibitor calphostin C. These results suggest that activation of protein kinase C by phorbol 12,13-dibutyrate leads to the desensitization of mu-, but not epsilon-opioid receptor-mediated antinociception. These findings also provide additional evidence for differential intracellular modulation on antinociceptive action of mu- and epsilon-opioid receptor agonists.

[Met5]enkephalin and delta2-opioid receptors in the spinal cord are involved in the cold water swimming-induced antinociception in the mouse

Mice made cold water swimming (CWS: 4 degrees C, 3 min) produced an opioid-mediated antinociception. Experiments were designed to determine what types of opioid receptors and endogenous opioid peptides in the spinal cord are involved in the CWS-induced antinociception in male ICR mice. Antinociception was measured by the tail-flick test. CWS-induced antinociception was blocked by intrathecal (i.t.) pretreatment with antiserum to [Met5]enkephalin (100 microg, 1 hr), but not by antiserum (100 microg, 1 hr) to [Leu5]enkephalin, beta-endorphin or dynorphin A (1-17). Moreover, i.t. pretreatment with delta2-opioid receptor antagonist naltriben (NTB: 10 microg, 10 min) blocked the antinociception induced by CWS or i.t.-administered [Met5]enkephalin (10 microg). However, the antinociception induced by CWS or i.t.-administered [Met5]enkephalin was not blocked by i.t. pretreatment with delta1-opioid receptor antagonist 7-benzylidene naltrexone (BNTX: 1 microg, 10 min), mu-opioid receptor antagonist D-Phe-Cys-Try-D-Try-Om-Thr-Phe-Thr-NH2 (CTOP: 50 ng, 10 min), or kappa-opioid receptor antagonist norbinaltorphimine (norBNI: 5 microg, 24 hr). These data indicate that [Met5]enkephalin and delta2-opioid receptor in the spinal cord are involved in antinociception induced by CWS.

A natural variant of bovine dopamine beta-monooxygenase with phenylalanine as residue 208: purification and characterization of the variant homo- and heterotetramers of (F208)4 and (F208)2(L208)2

Bovine dopamine beta-monooxygenase was purified from each of 18 individual adrenal glands by the method we have developed for the rapid purification of the enzyme from a single adrenal gland. Differential peptide mapping of the 18 enzyme preparations following fluorescence labeling of their cysteine residues revealed the presence of a novel variant with Phe as residue 208 in 14 adrenal glands; seven of them were homozygous for the variant allele and the remaining seven heterozygous. The variant enzyme was a tetramer and exhibited kinetic and structural properties similar to those of the wild-type tetramer (L208)4. These results indicate an allelic polymorphism and codominant expression of the two alleles of the enzyme gene.

High prevalence of a 30-base pair deletion and single-base mutations within the carboxy terminal end of the LMP-1 oncogene of Epstein-Barr virus in the Japanese population

The presence of 30-base pair (bp) deletion mutants within the carboxy terminal end of the LMP-1 oncogene (BNLF-1 gene) of Epstein-Barr virus (EBV) has been reported in EBV-associated neoplasms. We analysed the 30-bp deletion and the single-base mutations of the LMP-1 gene in 13 spontaneously established lymphoblastoid cell lines (LCLs) from peripheral blood mononuclear cells of three healthy children, four patients with EBV-unrelated acute febrile illnesses, three patients with infectious mononucleosis (IM), and three patients with chronic active EBV infection (CEBV), and six frozen samples from four patients with CEBV and two patients with EBV-associated hemophagocytic syndrome (EBV-AHS). For molecular analysis of the carboxy terminal end of the LMP-1 gene, PCR was performed using primers spanning the carboxy terminal region of the LMP-1 gene. Direct sequence analysis of the PCR products revealed identical 30-bp deletion in 14 of 19 samples (74%). Six point mutations at nucleotide positions 168357, 168355, 168320, 168308, 168295, and 168225 were frequently identified regardless of disease status. Our findings revealed the carboxy terminal end of the LMP-1 gene was mutational hot spots. The 30-bp deletion mutant is widely spread in the Japanese population and is not implicated in EBV-associated lymphoproliferative diseases.

Hyperalgesia induced by pituitary adenylate cyclase-activating polypeptide in the mouse spinal cord

The aim of the present study was to evaluate the distribution of pituitary adenylate cyclase-activating polypeptide (PACAP)-like immunoreactivity in the mouse spinal cord using an antibody against PACAP38 and to determine the behavioral profile, particularly with respect to hyperalgesia, of PACAP38 given intrathecally (i.t.) in the mouse. Immunoreactivity to PACAP38 was detected in numerous nerve fibers in the superficial layers of the dorsal horn of cervical, thoracic, lumbar and sacral segments and a few fibers extended into the deeper layers of the spinal cord. In addition, PACAP-like immunoreactivity were seen in the intermediolateral cell column of the thoracic and sacral segments. In behavioral studies, PACAP38 (0.05-0.5 microgram) produced a dose-dependent decrease of the tail-flick latency when given i.t. in the mouse. At higher doses (1-10 micrograms), PACAP38 given i.t. elicited biting and scratching behaviors lasting 10-20 min after the injection. PACAP at high doses (1-10 micrograms) also produced licking at tail, paw and penis and intense grooming behaviors immediately after the i.t. injection. Similar to substance P, these behaviors produced by PACAP can be considered as pain-like syndrome. These findings suggest that PACAP may be a sensory neurotransmitter involved in nociceptive signalling in the mouse spinal cord.

Primary gastric lymphomas: morphologic, immunohistochemical and immunogenetic analyses

Morphologic, immunohistochemical and immunogenetic studies were performed on 28 cases of primary gastric lymphoma from fresh frozen tissue. Eight cases were diagnosed as diffuse large B-cell lymphoma, four as follicular center lymphoma (follicular), five as mucosa-associated lymphoid tissue (MALT) lymphoma, three as plasmacytoma, and three as T-cell lymphoma, two as mantle cell lymphoma, one as follicular center lymphoma (diffuse, predominantly small cell), and one as lymphoplasmacytoid lymphoma, and one as Hodgkin's disease. From immunohistochemical studies, four types of morphologically similar low-grade lymphomas can be differentiated by a combination of various monoclonal antibodies. Cases of diffuse large B-cell lymphoma may have a germinal center origin. We observed lympho-epithelial lesions in cases of non-MALT lymphomas. We therefore consider that the current diagnostic criterion for MALT lymphoma may not always be valid. Except for cases of T-cell lymphoma and Hodgkin's disease, 17 out of 22 cases revealed clonal rearrangement bands of the JH gene. In situ hybridization (ISH) and polymerase chain reaction (PCR) studies revealed the presence of Epstein-Barr (EB) virus genomes in two and three cases, respectively. Epstein-Barr virus may play a role in lymphomagenesis, although on relatively rare occasions.

[Quantitative measurements of cerebral blood flow using 99mTc-ECD radionuclide angiography, SPECT and one-point arterial sampling]

We quantified regional cerebral blood flow using 99mTc-bicisate ethyl cysteinate dimer (ECD) radionuclide (RN) angiography, one-point arterial sampling and static SPECT in 12 patients. The tracer was injected as a bolus into the right antecubital vein, and time-activity curves over the cerebrum and the aortic arch were sequentially recorded for 300 s with 3 s intervals in a 128 x 128 format with a large-field of view gamma camera equipped with a low-energy collimator. Blood was obtained from the femoral artery immediately after stopping the RN angiography and the arterial concentration of 99mTc-ECD was calculated. Thereafter, the SPECT data acquisition was started with the subject's head immobilized. We applied a three-compartment kinetic model: The influx constant of 99mTc-ECD from blood to brain (K1) and the transfer of ECD from diffusible compartment to nondiffusible one in the blood (k5). The K1 value was compared with the global cerebral blood flow value (Fa) measured by the 133Xe clearance technique. From the kinetic analysis, the following parameter values could be calculated: K1 = 0.21 +/- 0.05 (ml/ml/min), k5 = 0.66 +/- 0.15 (/min), Fa = 0.32 +/- 0.09 (ml/ml/min) and the extraction fraction E = K1/Fa = 0.65 +/- 0.05. There was a strong correlation between K1 and Fa (Y = 0.53X + 3.7; rs = 0.91). By combining the K1 and E values in the whole-brain, we can obtain the absolute global flow value and regional 99mTc-ECD CBF maps if the average concentration of the tracer in the whole-brain is used as a reference. Our method is less invasive and suitable for quantitation of cerebral blood flow in patients with brain disorders.

Survey of mycoplasmal bacteremia detected in children by polymerase chain reaction

To determine whether mycoplasmal bacteremia occurs during ordinary or complicated diseases due to M. pneumoniae (and if so, how frequently), we used polymerase chain reaction (PCR) to detect M. pneumoniae in serum samples. The PCR primers used were modified for nested amplification. The genome of this organism was detected in 1 of the 25 patients with pneumonia and 10 of the 17 patients without pneumonia (P < .001, chi test). The genome was detected more frequently in patients who had encephalitis of which the neurological onset was within 7 days of the onset of fever rather than later. We hypothesize that mycoplasmal bacteremia occurs more frequently than previously appreciated, specifically in the absence of pneumonia, and that certain types of complications (e.g., encephalitis of early onset) are associated with its occurrence.

Postoperative lower limb paralysis due to retractors

We report a case of femoral neuropathy caused by retractors used during operation. The patient (a 74-year-old woman) was scheduled for right hemicolectomy for cecum cancer, and anesthesia was maintained with nitrous oxide and sevoflurane in oxygen plus extradural anesthesia. After operation, the patient complained of hypesthesia in the anterolateral and medial area governed by the femoral nerve. Magnetic resonance imaging findings, were normal and the straight leg raising test was negative. After 2 months, the patient had completely recovered from the neurological symptoms. These manifestations were indicative of femoral neuropathy resulting from the pressure of large-bladed self-retraining retractors. It is important to include femoral neuropathy in the differential diagnosis of postoperative paralysis of the lower limb.

Phorbol ester blocks the increase of a high affinity GTPase activity induced by delta 2-opioid receptor agonist in the mouse spinal cord

The high affinity GTPase activity in the mouse spinal cord was increased in a concentration-dependent manner by a selective delta 2-opioid receptor agonist, [D-Ala2]deltorphin II (0.1-1 microM). This increase of GTPase activity induced by [D-Ala2]deltorphin II was completely blocked by co-incubation with a selective delta 2-opioid receptor antagonist, naltriben (0.1 microM). A protein kinase C activator, phorbol 12,13-dibutyrate (PDB; 0.1-10 microM), which given alone had no effect on basal GTPase activity, blocked dose-dependently the increase of GTPase activity induced by [D-Ala2]deltorphin II (1 microM). Our results indicate the possibility that activation of protein kinase C by phorbol ester uncouples the delta 2-opioid receptor from G-proteins in the spinal cord.

Role of protein kinase C in desensitization of spinal delta-opioid-mediated antinociception in the mouse

1. Receptor phosphorylation and down-regulation by protein kinases may be a key event initiating desensitization. The present studies were designed to investigate the effect of a potent protein kinase C (PKC) activator, phorbol 12,13-dibutyrate (PDBu), on antinociception induced by intrathecal (i.t.) administration of a selective delta-opioid receptor agonist [D-Ala2] deltorphin II in the male ICR mouse and on the specific binding of [3H]-[D-Ser2, Leu5]enkephalin-Thr6 (DSLET), a delta-opioid receptor ligand, in the crude synaptic membrane of the spinal cord. 2. Intrathecal (i.t.) pretreatment with PDBu at low doses, which injected alone did not affect the basal tail-flick latency, dose-dependently attenuated the antinociception induced by i.t. administration of [D-Ala2]deltorphin II. The attenuation of i.t.-administered [D-Ala2] deltorphin II-induced antinociception by PDBu was reversed in a dose-dependent manner by i.t. concomitant pretreatment with a specific PKC inhibitor, calphostin C. 3. In the binding experiment, incubation of the crude synaptic membrane of the spinal cord for 2 h at 25 degrees C with PDBu (0.03 to 10 microM) caused a dose-dependent inhibition of the [3H]-DSLET binding. Scatchard analysis of [3H]-DSLET binding revealed that PDBu at 10 microM displayed a 30.7% reduction in the number of [3H]-DSLET binding sites with no significant change in affinity, compared with the non-treatment control, indicating that the activation of membrane-bound PKC by PDBu causes a decrease in the number of specific delta-opioid agonist binding sites. 4. An i.t. injection of [D-Ala2]deltorphin II produced an acute antinociceptive tolerance to the antinociceptive effect of a subsequent i.t. challenge of [D-Ala2]deltorphin II. Concomitant pretreatment with calphostin C markedly prevented the development of acute tolerance to the i.t.-administered [D-Ala2]deltorphin II-induced antinociception. On the other hand, a highly selective protein kinase A (PKA) inhibitor, KT5720, did not have any effect on the development of acute tolerance to [D-Ala2]deltorphin II antinociception. 5. These findings suggest that a loss of specific delta-agonist binding by the activation of PKC by PDBu is involved in the PDBu-induced antinociceptive unresponsiveness to delta-opioid receptor agonist in the mouse spinal cord. Based on the acute tolerance studies, we propose that PKC, but not PKA, plays an important role in the process of homologous desensitization of the spinal delta-opioid receptor-mediated antinociception.

Pathologic changes in closed porcine intestinal loops inoculated with Aujeszky's disease virus

Development of enteric lesions in closed jejunal and ileal loops inoculated with Aujeszky's disease virus (ADV) was examined in four 6-week-old SPF pigs. A large number of ADV antigens were detected first in necrotic foci in the subepithelial areas, and subsequently in the epithelial cells, lymphoid follicles in Peyer's patches and neuronal cells of Meissner's and Auerbach's plexuses.

Pretreatment with pertussis toxin spinally, but not supraspinally, blocks the cold water swimming-induced antinociception in the mouse

Mice exposed to cold water swimming (4 degrees C) for 3 min produced a marked antinociception. Experiments were designed to determine whether pretreatment with pertussis toxin given intrathecally (i.t.) or intracerebroventricularly (i.c.v.) attenuates cold water swimming-induced antinociception in male ICR mice. Antinociception was measured by the tail-flick test 7 min after cold water swimming. I.t. pretreatment with pertussis toxin at a dose of 0.5 microgram for 24-96 h caused a time-dependent attenuation of cold water swimming-induced antinociception. Moreover, i.t. pretreatment with pertussis toxin at doses from 0.125 to 0.5 microgram for 96 h attenuated cold water swimming-induced antinociception in a dose-dependent manner. However, i.c.v. pretreatment with pertussis toxin at doses from 0.125 to 0.5 microgram for 24-96 h did not affect the cold water swimming-induced antinociception. The present results suggest that pertussis toxin-sensitive Gi/G(o) proteins in spinal cord, but not at the supraspinal sites, are involved in cold water swimming-induced antinociception.

Selective cleavage and modification of the intersubunit disulfide bonds of bovine dopamine beta-monooxygenase: conversion of tetramer to active dimer

Bovine dopamine beta-monooxygenase is a tetramer consisting of two disulfide-linked dimers. To examine the role(s) of the intersubunit disulfide bonds in the protein structure and activity, the enzyme was treated with DTT at pH 7.5 and 25 degrees C under nondenaturing conditions. A 15-min incubation with 0.5 mM DTT selectively cleaved half of the intersubunit disulfide bonds. The cleavage did not affect the activity or tetrameric structure of the enzyme. Upon chemical modification of the reduced cysteine residues with 0.1 M iodoacetamide (IAA) for 60 min, half of the tetramer was converted to a dimeric species. The resulting dimeric and tetrameric species exhibited similar kinetic properties, and the Vmax values were decreased by 30% compared to that of the native enzyme. Upon treatment with IAA alone, no dimer species was detected but the enzyme lost 30% of the original activity. Cys514 and Cys516 were selectively modified by the treatment with DTT and IAA. From these results, we concluded that: (i) chemical modification of the intermolecular disulfide bonds strongly destabilizes the intersubunit interaction; (ii) breakage of the intersubunit interaction does not affect the activity. The reduction mechanism of the intersubunit disulfide bonds and the roles of the intersubunit interactions are discussed.

[Regional left ventricular contraction kinetics in patients with hypertrophic cardiomyopathy: investigation by ECG-gated myocardial SPECT with 99mTc-MIBI]

To investigate the regional left ventricular (LV) contraction kinetics in patients with hypertrophic cardiomyopathy (HCM), we performed ECG gated myocardial tomography (gated-SPECT) with 99mTc methoxy-2-isobutyl isonitrile (MIBI) at rest in 11 patients with HCM and 13 normal subjects. In order to evaluate regional LV contraction kinetics, multi-plane long axial tomograms were constructed and LV was divided into 17 segments. From the time activity curve of myocardial count, percent change during systole (%CC) was calculated in each segment. Normal range of %CC in each segment was derived from normal files. Systolic asynchrony in each patient was expressed as SD (standard deviation) of R-wave to peak count (R-PC) intervals of 17 segments. Decreased %CC was observed in 87 of 187 segments (47%) in HCM (8 +/- 5 segments/patient, range; 2-14 segments/patient). SD in patients with HCM was significantly greater than that in normal subjects (5.9 +/- 1.3 vs. 3.5 +/- 0.6, p < 0.01). The extent of decreased %CC in patients with HCM correlated well with global 123I-BMIPP (BMIPP) uptake and the extent of regional abnormality of BMIPP (Defect Score) (r = -0.79, r = 0.88 each, p < 0.01). On the other hand, SD correlated well with left ventricular (LV) filling rate during early diastole (r = -0.66, p < 0.01). Patients with HCM were divided into 2 groups whether LV ejection fraction (EF) increased (Group 1) or decreased (Group 2) by exercise stress. SD in Group 2 was significantly greater than that in Group 1. In segments with decreased %CC, the distribution of R-PC interval was different with that in segments with normal %CC. These results suggested that indexes which were derived from gated-SPECT with MIBI could bring several informations which were important to assess the pathologic condition of HCM.

Use of antisense oligodeoxynucleotide to determine delta-opioid receptor involvement in [D-Ala2]deltorphin II-induced locomotor hyperactivity

Intracerebroventricularly (i.c.v.)-administered [D-Ala2]deltorphin II (20 micrograms) produced a marked locomotor hyperactivity in male ICR mice. The locomotor hyperactivity induced in response to i.c.v. [D-Ala2]deltorphin II (20 micrograms) was suppressed by pretreatment with naltriben (NTB, 10 micrograms) but not 7-benzylidene naltrexone (BNTX, 1 microgram) and D-Phe-Cys-Tyr-D-Try-Orn-Thr-Phe-Thr-NH2 (CTOP, 100 ng). The influence of antisense oligodeoxynucleotide to delta-opioid receptor mRNA (delta-AS oligo) or a mismatch oligodeoxynucleotide (MM oligo) on the locomotor hyperactivity induced by [D-Ala2]deltorphin II was determined. Groups of mice pretreated i.c.v. with delta-AS oligo (1 microgram), MM oligo (1 microgram) or saline (4 microliters) once a day for 3 days, were injected i.c.v. [D-Ala2]deltorphin II (10 or 20 micrograms) and the locomotor response to [D-Ala2]deltorphin II was measured. The locomotor hyperactivity of i.c.v. [D-Ala2]deltorphin II (10 or 20 micrograms) were significantly suppressed by i.c.v. pretreatment with delta-AS oligo but not MM oligo. The present results indicate that pretreatment with delta-AS oligo suppresses mouse locomotor hyperactivity produced by stimulation of delta 2-opioid receptors in the brain.

Pyothorax-associated lymphoma. An unusual case with biphenotypic character of T and B cells

Pyothorax-associated lymphoma is known to develop in patients who received an artificial pneumothorax for pulmonary tuberculosis some 30 to 40 years previously. Such patients exhibit large, immunoblastic lymphoma cells and often have a B-cell phenotype. We present a patient with an artificial pneumothorax and such a late developing lymphoma but with the unique finding of aberrant T- and B-cell phenotypes. Southern blot hybridization using immunoglobulin gene JH and T-cell receptor beta chain receptors revealed germline configurations. Lymphomas developing in immunocompromised patients, such as those with acquired immunodeficiency syndrome, may show such unusual phenotypes. The unusual phenotypes found in this patient provide evidence that his pyothorax-associated lymphoma was related to an immunocompromised state.

Demonstration of infectious bovine rhinotracheitis virus antigen by immunoperoxidase method in tissues of aborted bovine fetuses preserved for 25 years in paraffin blocks

Infectious bovine rhinotracheitis (IBR) virus antigen was demonstrated by the immunoperoxidase method in tissues of two aborted bovine fetuses, which had been stored for 25 years after fixing in formalin and embedding in paraffin. Necrotic foci were detected in the liver, kidney, adrenal gland, and thymus of the fetuses. Coincidenting with the distribution of the necrotic foci, IBR virus antigen was demonstrated by immunostaining. The present study proved the immunoperoxidase method in one of useful techniques to demonstrate IBR virus antigen in tissue sections from preserved paraffin blocks.