Localization of the gene (SLC1A3) encoding human glutamate transporter (GluT-1) to 5p13 by fluorescence in situ hybridization

The glutamate transporter takes up glutamate to terminate neurotransmission and to prevent neuronal cell death. Chromosomal location of the human glutamate transporter, hGluT-1, gene (SLC1A3) was determined by fluorescence in situ hybridization. SLC1A3 was mapped to chromosome 5p13.

Potentiation of cholecystokinin-induced amylase release by peptide VIP in guinea pig pancreatic acini

The mechanism of the potentiating effect of vasoactive intestinal peptide (VIP) on cholecystokinin (CCK-8)-induced amylase release was studied in isolated and perifused pancreatic acini of the guinea pig. VIP (30 pM-10 nM) potentiated CCK-8 (100 pM)-induced amylase release. Unexpectedly, VIP inhibited CCK-8-induced intracellular Ca2+ oscillations. Forskolin (10 microM), an activator of adenylate cyclase, potentiated CCK-8 (100 pM)-induced amylase release with a time course similar to that observed with VIP. Caffeine (20 mM) inhibited both amylase release and Ca2+ oscillations in response to CCK-8, suggesting that inhibition of Ca2+ oscillations does not necessarily lead to a potentiation of amylase release. When intracellular Ca2+ concentration ([Ca2+]c) was raised by thapsigargin (10 microM), a selective inhibitor of Ca(2+)-ATPase in the endoplasmic reticulum (ER), VIP (10 nM) induced significantly greater amylase release than that induced by VIP alone. When [Ca2+]c was lowered by preincubation with BAPTA-AM (25 microM), a cell-permeant Ca2+ chelator, VIP-induced amylase release was completely abolished. These results suggest that VIP, in spite of its inhibitory action on Ca2+ oscillations, facilitates a Ca(2+)-dependent process distal to the increase in [Ca2+]c to potentiate CCK-8-induced amylase release.

Size and position invariance of neuronal responses in monkey inferotemporal cortex

1. Object vision is largely invariant to changes of retinal images of objects in size and position. To reveal neuronal mechanisms of this invariance, we recorded activities from single cells in the anterior part of the inferotemporal cortex (anterior IT), determined the critical features for the activation of individual cells, and examined the effects of changes in stimulus size and position on the responses. 2. Twenty-one percent of the anterior IT cells studied here responded to ranges of size > 4 octaves, whereas 43% responded to size ranges < 2 octaves. The optimal stimulus size, measured by the distance between the outer edges along the longest axis of the stimulus, ranged from 1.7 to 30 degrees. 3. The selectivity for shape was mostly preserved over the entire range of effective size and over the receptive field, whereas some subtle but statistically significant changes were observed in one half of the cells studied here. 4. The size-specific responses observed in 43% of the cells are consistent with recent psychophysical data that suggest that images of objects are stored in a size-specific manner in the long-term memory. Both size-dependent and -independent processing of images may occur in anterior IT.

Human proteasome subunits from 2-dimensional gels identified by partial sequencing

Human proteasomes consist of 14 major subunits which can be resolved by two-dimensional polyacrylamide gel electrophoresis. Tryptic peptides from the subunits were sequenced. This allowed identification of all proteins in two-dimensional electrophoresis gels with proteasome subunits whose sequences are known from cDNA. The results also precisely define the specificity of a panel of subunit-specific monoclonal antibodies. A new proteasome subunit (Z) was discovered. In contrast, the putative subunit MECL-1 could not be detected in human placenta proteasomes.

Inhibition of the T-cell receptor-mediated signal transduction by microinjection of anti-Lck monoclonal antibody into T-cells

Engagement of T-cell receptor (TcR)/CD3 complexes on T-cells rapidly provokes tyrosine phosphorylation of cellular proteins, which is thought to be an essential step to the following events of T-cell activation. p56lck, a member of src-related, non-receptor type protein tyrosine kinases, is expressed predominantly in lymphocytes. Accumulating data suggest that p56lck is one of the kinases responsible for TcR-mediated protein tyrosine phosphorylation. To investigate the role of p56lck in TcR-signaling in detail, we injected anti-Lck monoclonal antibody (mAb), MOL171 or MOL294, both specifically suppress Lck kinase activity in vitro, into Jurkat T-cells by the erythrocyte-ghost procedure in order to block the activity of p56lck. In Jurkat cells injected with anti-Lck mAb, intracellular Ca2+ mobilization induced by TcR-stimulation was markedly reduced in comparison with control mouse IgG-injected samples. This block of Ca2+ influx seems to be specific for TcR-signaling because anti-Lck mAb-injection did not cause significant suppression of phytohaemagglutinin-induced Ca2+ increase. Furthermore, injection of anti-Lck mAb inhibited TcR-mediated protein tyrosine phosphorylation of 100 kDa protein and phospholipase C gamma 1. These results confirm that p56lck is an indispensable element of TcR-signaling and p100 and phospholipase C gamma 1 are strongly presumed to be candidates for substrates for p56lck.

Passive transfer and active immunization with the recombinant leucine-zipper (Yo) protein as an attempt to establish an animal model of paraneoplastic cerebellar degeneration

Passive transfer of paraneoplastic cerebellar degeneration (PCD) IgG to rodents as well as active immunization with recombinant Yo fusion protein were tried in order to examine the roles of anti-Purkinje cell antibody (anti-Yo antibody) present in the sera and cerebrospinal fluid of patients with PCD in Purkinje cell loss, the hall mark of PCD pathology. On a single injection of PCD IgG to mouse brain, IgG was taken into Purkinje cells and remained there for more than 36 h without Purkinje cell loss. Injection of PCD IgG together with complement or lipopolysaccharide-activated human macrophages or rat mononuclear cells to rats ventricles did not cause Purkinje cell loss. We made a recombinant Yo fusion protein that has the leucine-zipper protein (Yo protein), the common epitope for anti-Yo antibody. Mice immunized with this Yo protein produced high titer antibody against it for more than 3 months, during which time neither neurological symptoms nor Purkinje cell loss occurred. The anti-Yo antibody, with or without complement or activated mononuclear cells, therefore could not be the sole cause of Purkinje cell loss.

Cloning, analysis and expression of an rpoS homologue gene from Pseudomonas aeruginosa PAO1

A homologue of the rpoS gene of Escherichia coli was cloned from Pseudomonas aeruginosa PAO1 by hybridization with an oligodeoxyribonucleotide probe designed from an amino-acid stretch conserved among the principal sigma factors of eubacteria. Two open reading frames, the pcm gene and the orf-297 of unknown function, were found in the upstream region of rpoS, and in the same order as in E. coli. The rpoS gene of P. aeruginosa was expressed in E. coli and complemented the catalase deficiency of the rpoS mutant of E. coli. The RpoS protein of P. aeruginosa was identified by Western blot analysis in both P. aeruginosa (Pa) and the transformed E. coli. Levels of RpoS of Pa increased drastically at the onset of the stationary growth phase.

Marked increase in glutamate-aspartate transporter (GLAST/GluT-1) mRNA following transient retinal ischemia

We have demonstrated the cellular localization of glutamate-aspartate transporter (GLAST/GluT-1) mRNA in the rat retina and its induction after ischemia by in situ hybridization. GLAST mRNA was expressed in the inner two-thirds of the inner nuclear layer (INL) and in sparse small cells in the inner portion of the ganglion cell layer (GCL) of the adult rat retina. GLAST mRNA was also found in about 90% of cells in the optic nerve head where more than 90% of cells express glial fibrillary acidic protein (GFAP) mRNA. Moreover, experimental occlusion of the central retinal artery followed by reperfusion for 48 h resulted in degeneration of neurons and a marked increase in GLAST mRNA expression in the INL. These findings suggest that GLAST may be expressed in Müller cells and astrocytes in the retina, and may play an important role in regulation of extracellular glutamate concentration especially under ischemic conditions.

Studies on thermophile products. XI. Biological effect of antigen presenting inhibitor, isofatty acid-containing phosphatidylethanolamine, on mouse macrophages

A new fraction, Fr. 8-A, which consists of a phosphatidylethanolamine with C14:0-C18:0 isofatty acids was obtained from Bacillus stearothermophilus UBT8038. The fraction inhibited major histocompatibility complex class II (Ia) antigen expression and antigen presentation on mouse macrophages. The effect of Fr.8-A on macrophage functions related to antigen presentation was investigated. Fr. 8-A increased arachidonate release, prostaglandin (PG) E2 release and nitrite production from peritoneal macrophages. It increased further the levels of PGE2, nitrite and tumor necrosis factor in the culture supernatant of the macrophages induced by the supernatant from concanavalin A-stimulated spleen cell cultures. Fr. 8-A augmented the activity of peritoneal macrophages to suppress Con A-stimulated T cell proliferation. Addition of either indomethacin or Ng-methyl-L-arginine had no effect on the augmentation of suppressor macrophage activity or the inhibition of antigen presentation by Fr. 8-A, while simultaneous addition of both inhibitors abrogated the effect of the fraction. These results indicate that Fr. 8-A inhibits Ia expression and antigen presentation, and augments suppressor macrophage activity at least partly via the activation of both cyclooxygenase and nitric oxide synthase pathways.

Calcium transients in single myocytes and membranous ultrastructures during the development of cardiac hypertrophy and heart failure in rats

1. We examined changes in intracellular calcium transients of separated single myocytes from the right ventricle (RV) of the rat heart during the change from adaptation to maladaptation in response to a pressure overload. 2. Right ventricular hypertrophy (RVH) secondary to pulmonary hypertension was induced by a subcutaneous injection of monocrotaline. Developed tensions of the RV-free wall were decreased as RVH progressed. Single myocytes were separated from the RV during different stages of RVH. Fura-2/AM-loaded cells were field stimulated, and changes in calcium transients were measured by Olympus OSP-3 system. We also examined membranous ultrastructures (sarcoplasmic reticulum, mitochondria, surface caveolae) involved in calcium metabolism in the hearts using scanning electron microscopy. 3. We observed characteristic changes in calcium transients during the change from adaptation to maladaptation, and also found that one parameter (amplitude) of calcium transients appeared to be correlated with the changes in the number of sarcoplasmic reticulum. 4. These results provided some insights into the mechanism of calcium handling of hypertrophied heart in response to a pressure overload from adaptation to maladaptation especially when stimulatory frequency was high, and suggested that heart rate control is a very important factor for the treatment of patients with congestive heart failure.

Long-term results of valve replacement with the St. Jude Medical valve

Between 1980 and 1992, 908 patients underwent single aortic (n = 178), single mitral (n = 577), or double aortic and mitral (n = 153) valve replacement with the St. Jude Medical valve at our hospital. There were 392 male patients and 516 female patients whose ages ranged from 1.2 to 74 years (mean, 52 years). The early mortality rate was 5.0% (45 patients). A 94% complete follow-up was accomplished for 863 patients who were discharged from the hospital (4682.3 patient-years). Sixty-nine of these patients died, for a late mortality rate of 8.0%. Fifty-two patients, including four patients (0.3%/100 patient-years) had anticoagulant-related hemorrhage, 4(0.1%/100 patient-years) had prosthetic valve endocarditis, 11 (0.2%/100 patient-years) had nonstructural valve dysfunction, and 16 (0.3%/100 patient-years) underwent reoperation. There were no structural valve failures in this series. The total number of valve-related deaths was 22. Of those patients who survived, 98% were in New York Heart Association functional class I or II at the date of the last follow-up. The probabilities of freedom from thromboembolism and anticoagulant-related hemorrhage at 10 years were 94% +/- 2% and 97% +/- 2% in aortic valve replacement, 89% +/- 2% and 98% +/- 4% in mitral valve replacement, and 89% +/- 6% and 92% +/- 6% in double valve replacement, respectively. Significant hemolysis related to the St. Jude Medical valve occurred in 8 of the 577 patients who received mitral valve replacement in our early experience, and modifying the valve orientation appeared to play an important role in reducing hemolysis. The event-free rate, including all complications and late deaths, at 10 years was 75% +/- 7%, 74% +/- 3%, and 81% +/- 6% in aortic valve replacement, mitral valve replacement, and double valve replacement, respectively. On the basis of these results, the St. Jude Medical valve seems to be an excellent mechanical valve in terms of durability and low thrombogenicity and remains our prosthetic valve of choice when valve replacement with a mechanical valve is indicated.

Popliteal venous aneurysm with pulmonary embolism

A 29-year-old female was admitted to the hospital because of increasing exertional dyspnea, chest oppressive feeling and palpitation. Lung perfusion scan, pulmonary angiography, and venography of the lower extremities revealed multiple pulmonary embolism and a right popliteal venous aneurysm as the probable source of emboli. B-mode/Doppler echography and magnetic resonance imaging were useful for the preoperative evaluation. Following anticoagulant therapy and thrombolytic therapy using intravenous heparin and urokinase, respectively, the popliteal venous aneurysm was surgically excised; the walls contained organized thrombus. She delivered a baby without any complication 2 years after the surgery.

Contrasting effects of isoproterenol and phosphodiesterase III inhibitor on intracellular calcium transients in cardiac myocytes from failing hearts

1. Effects of a newly developed phosphodiesterase (PDE) III inhibitor, E-1020, on intracellular calcium transients were compared with those of isoproterenol (ISO) in isolated single myocytes from failing hearts secondary to pulmonary hypertension induced by monocrotaline injection. Myocytes were isolated by enzyme digestion using a Langendorff apparatus. Changes in intracellular calcium concentrations ([Ca2+]i) were recorded using a fura-2 fluorescence microscopic technique. Cyclic AMP contents of the hearts were measured by radio-immunoassay. 2. Myocytes from failing hearts showed Ca2+ transients with a low peak (low amplitude) and delayed decline of Ca2+ transients. Both ISO and E-1020 increased peak [Ca2+]i, max + d[Ca2+]i/dt, and max - d[Ca2+]i/dt in a concentration-dependent manner while both agents decreased T80L (time to 80% decline of amplitude from peak light). The concentrations which increased peak [Ca2+]i by 50% were 1.6 x 10(-9) mol/L of ISO and 2 x 10(-6) mol/L of E-1020. These concentrations increased cAMP in the heart to the same levels. Analysis of the effects of both agents on peak [Ca2+]i versus max - d[Ca2+]i/dt showed that ISO is much more effective on peak [Ca2+]i while E-1020 is more effective on max - d[Ca2+]i/dt. 3. These results showed that the effects of ISO and E-1020 on the parameters of intracellular Ca2+ transients of single myocytes from failing hearts are slightly different, and suggest that E-1020 may improve diastolic function as well as systolic function in failing hearts.

Effect of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on hepatic cholesterol 7 alpha-hydroxylase, acyl-coenzyme A: cholesterol acyltransferase, and bile lipid secretion in the hamster with intact enterohepatic circulation

The effects of administration of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on hepatic cholesterol 7 alpha-hydroxylase and acyl-coenzyme A: cholesterol acyltransferase (ACAT) activities and bile lipid secretion were investigated in Syrian golden hamsters. Continuous administration of pravastatin induced no significant changes in hepatic cholesterol content, ACAT and cholesterol 7 alpha-hydroxylase activities, or bile lipid and acid composition. Abrupt withdrawal of pravastatin induced increases in hepatic cholesterol content and ACAT activity and no change in hepatic cholesterol 7 alpha-hydroxylase activity, and increased cholesterol saturation in bile. Hepatic cholesterol 7 alpha-hydroxylase activity paralleled hepatic mRNA levels of this enzyme. These results suggest that a change in hepatic cholesterol metabolism induced by continuous administration of pravastatin maintains a constant net balance of hepatic cholesterol content. In addition, the drug has no deleterious influence on metabolism of bile lipids and acids and related enzymes, except for a transient increase in cholesterol saturation in bile induced by an inappropriate increase in hepatic cholesterol content and a lack of response of cholesterol 7 alpha-hydroxylase activity to changes in hepatic cholesterol content upon abrupt withdrawal of pravastatin.

Biochemical and biophysical alterations of lipoprotein after liver transplantation from a living related donor. A biochemical and proton NMR study

Changes in lipoprotein metabolism after liver transplantation from living related donors were investigated in nine pediatric patients by means of biochemical and proton nuclear magnetic resonance (NMR) analyses of lipoprotein. NMR offers rapid and nondestructive measurement of lipoprotein. The ratio of esterified cholesterol to total cholesterol, expected to be a prognostic indicator after liver transplantation, was low before the operation (0.44) and recovered to over 0.6 at 3 weeks. The half line width of the methylene peak of lipoprotein, as measured by proton NMR, was correlated with the ratio of esterified cholesterol to total cholesterol. It is suggested that proton NMR analysis can provide information about the biophysical changes in lipoprotein associated with liver transplantation.

[Perinatal outcome of pregnancies following therapy of infertility]

To evaluate the risks involved in post infertility pregnancy, the perinatal outcomes of 571 patients with infertility treatment in 9 institutions were analyzed by questionnaire retrospectively. The rate of multiple pregnancy and premature delivery was 14.5% (83/571) and 13.3% (76/571) respectively. Multiple pregnancies occurred in 33 cases with ovulation induction, 22 cases with artificial insemination by the husband (AIH) and 25 cases with in-vitro fertilization by embryo transfer (IVF). Premature deliveries occurred in 32 cases with ovulation induction. 26 cases with AIH and 14 cases with IVF. Three babies were dead and 4 babies were handicapped. In single post infertility pregnancy, the rate of premature birth was twice as high (9.0%) as in normal controls. The mortality rate was 0.45% (2/449), which was higher than that of controls. This suggests that post infertility pregnancies tend to result in multiple pregnancy and premature birth. In addition, in single post infertility pregnancies there was the possibility of poor perinatal outcome.

Metabolism of illudin S, a toxic substance of Lampteromyces japonicus. IV. Urinary excretion of an illudin S metabolite in rat

1. The urinary excretion of a metabolite of illudin S after oral administration to rat has been studied. 2. From an ethyl acetate extract of urine, metabolite 1, a cyclopropane ring-cleavage compound, was identified by liquid chromatographic-mass spectrometric analysis 3. A hplc method for determination of the metabolite in rat urine was developed with extraction using Sep-Pak C18 cartridge followed by liquid-liquid extraction. 4. The metabolite excreted during 3 days after administration of illudin S to rat amounted to approximately 10-19% of the dose as free form and 3-5% of the dose as glucuronide.

[Multi-organ ischemia due to traumatic lesion of the descending thoracic aorta--a case-report]

This is a case of severe ischemic and reperfusion multi-organ failure due to descending thoracic aortic rupture. A 25 year-old man received a hard blow on his chest in a traffic accident. Chest X-ray, CT scans and aortogram elucidated descending thoracic aortic rupture. Emergency operation was performed 18 hours after the injury. The aortic rupture, 4/5 of the aortic circumference with intact adventitia was seen. The descending aorta 22 distal to the left subclavian artery was repaired under cardio-pulmonary bypass with selective cerebral perfusion. Ischemia due to aortic occlusion with thrombus and reperfusion injury after reconstruction of the aorta connected with rhabdmyolysis and severe multi-organ failure. Intestinal necrosis required laparotomy on the 9th and 15th post operative day. The patient died on 15th postoperative day of multi-organ failure.

Choriocarcinoma in a term placenta with pulmonary metastasis

This is a case report of choriocarcinoma in the placenta of a patient who had a term delivery at the 38th week of pregnancy. The pregnant woman had hemoptysis at the 26th week of pregnancy, and a chest X-ray revealed a tumor in the left lung. She had suffered from a hydatidiform mole in a previous pregnancy in 1989. The patient's serum level of beta-human chorionic gonadotropin (hCG) had been below the normal level before the present pregnancy. Choriocarcinoma was histologically found at 3 sites in the placenta. Her urine hCG levels decreased rapidly after delivery. A partial lobectomy was performed after 2 courses of chemotherapy, and no choriocarcinoma was recognized histologically, because the lesions were hemorrhagic and necrotic. At present, the mother is free of disease, and the baby is growing normally. The placenta should be examined in a detail in post-molar pregnancy.