Expression of the vascular endothelial growth factor (VEGF) receptor gene, KDR, in hematopoietic cells and inhibitory effect of VEGF on apoptotic cell death caused by ionizing radiation

Vascular endothelial growth factor (VEGF) has been identified as a peptide growth factor specific for vascular endothelial cells. In this study, we demonstrated the expression of the KDR gene transcript, which encodes a cell surface receptor for VEGF, in normal human hematopoietic stem cells, megakaryocytes, and platelets as well as in human leukemia cell lines, HEL and CMK86. Moreover, we showed the expression of VEGF gene transcript in these normal fresh cells and cell lines. To elucidate biological functions of VEGF on hematopoiesis, we determined whether this growth factor has mitogenic activity to hematopoietic cells or the ability to suppress apoptotic cell death. The liquid culture and colony-formation assay revealed that VEGF suppressed apoptotic cell death of both CMK86 cells and normal hematopoietic stem cells caused by gamma-ray irradiation, although mitogenic activity of VEGF was not detected. The ability of VEGF to suppress apoptotic cell death was independent of the change of cell cycle distribution. These data suggest that VEGF may play an important role in survival or maintenance of hematopoietic stem cells due to the prevention of apoptotic cell death caused by some stresses such as ionizing radiation and that VEGF may give leukemia cells some abilities of resistance against radiotherapy in an autocrine or paracrine manner.

Cloning of Corticium rolfsii glucoamylase cDNA and its expression in Saccharomyces cerevisiae

A cDNA coding for the glucoamylase of Corticium rolfsii AHU 9627 was cloned using synthetic oligonucleotide probes that code for inner amino acid sequences of the purified enzyme. This clone (CG 15) is 1900 base pairs long and contains the entire coding region for a polypeptide of 579 residues. Comparison with amino acid sequences of other fungal glucoamylases showed homologies of 35%-56%, and most homology with that of Aspergillus niger. The expression plasmid pACG 115 was constructed by introduction of the coding region of CG 15 into a yeast expression vector pAAH 5, containing the promoter and terminator of alcohol dehydrogenase (ADHI). Saccharomyces cerevisiae AH 22, containing the recombinant plasmid pACG 115, acquired starch-saccharifying ability.

[Evaluation of reliability of IPSS by 24-hour uroflowmetry]

BACKGROUND

Although the international prostate symptom score (IPSS) is now often used to assess the symptoms of BPH, whether or not patients answer the questions correctly has not been validated objectively.

METHODS

Reliability of IPSS was evaluated by 24-hour uroflowmetry in 20 hospitalized male patients. Six of them had prostatic hypertrophy or cancer, and the evaluation was performed before and after TURP or hormonal therapy in these six patients. The objective scores for frequency and nocturia were obtained from the time recorded on IC card. The objective score for intermittency was calculated from the uroflow curves.

RESULTS

The answer about frequency was not correct compared with the objective scores for frequency. The answers about nocturia and intermittency were almost the same as the corresponding objective scores. The answer for weak stream correlated with the average of peak flow rate. However, the threshold of peak flow rate for "weak stream" fluctuated markedly before and after the treatment in the same individuals. The answer for hesitancy had no correlation with the hesitation time. Patients seemed to understand the question translated in Japanese as "have you need force to urinate?"

CONCLUSION

Before wider use of IPSS in Japan, the correct translation of the questions and verification of the usefulness of the questions in large number of Japanese patients seem necessary.

Motor unit firing behavior in slow and fast contractions of the first dorsal interosseous muscle of healthy men

The motor unit recruitment threshold and firing rate were evaluated during slow and fast contraction of the first dorsal interosseous (FDI) muscle by healthy young men. Using a special quadrifilar electrode myoelectric activity was recorded during voluntary isometric contraction. Motor unit action potentials (MUAPs) were decomposed into individual MUAP trains by the electromyography (EMG) signal decomposition technique. Recruitment thresholds of the motor units decreased with the increase in the speed of contraction, and there was no recruitment reversal despite the increase. In terms of rate coding, the firing rates of the motor units increased as the speed of contraction increased; however, a high threshold motor unit always had a lower firing rate than a low threshold motor unit regardless of the contraction speed. At all contraction speeds, recruitment and rate coding may act through the same mechanism. If excitation of the motoneuron pool occurs rather than excitation of an individual motoneuron, a low threshold motor unit is easier to recruit and fire repetitively than a high threshold one. The motor unit firing behavior during fast contraction basically may be the same as during slow contraction.

Neonatal cholestasis in two siblings: a variant of Dubin-Johnson syndrome?

OBJECTIVE

Two Japanese brothers with neonatal cholestasis associated with pigment granules in the hepatocytes and hepatosteatosis were evaluated for the possible role of hepatosteatosis in the Dubin-Johnson syndrome.

METHODOLOGY AND RESULTS

The morphology of pigment accumulation and the laboratory data in these cases were examined. The elevation of urinary coproporphrin isomer I to more than 90% and the presence cholestasis resembled that in the Dubin-Johnson syndrome, but the hypertriglyceridaemia ( > 1.13 mmol/L as triolein) and the hepatosteatosis differed. Both infants were thought to have familial hypertriglyceridaemia. However, this diagnosis was difficult to confirm in the absence of data on the normal values of apolipoprotein and lipoprotein isomer for infants.

CONCLUSIONS

A neonatal variant of the Dubin-Johnson syndrome may account for the unusual findings in these infants.

Clinical characteristics of subacute thyroiditis classified according to human leukocyte antigen typing

We investigated human leukocyte antigen (HLA) class I and class II antigens in 56 Japanese patients with subacute thyroiditis (SAT) who visited our out-patient clinic between 1988 and 1990. We found SAT to be associated with not only HLA-B35 (40 patients; P < 0.000001; relative risk, 18.02), but also with HLA-B67 antigens (9 patients; P < 0.00001; relative risk, 11.20). No heterozygotes of HLA-B35 or HLA-B67 were found in any of the 56 patients with SAT. Either HLA-B35 or HLA-B67 antigen is found in 87% of patients with SAT. When season of onset and clinical course of SAT were compared in the 49 patients with HLA-B35-positive SAT (B35-SAT) and HLA-B67-positive SAT (B67-SAT), we were able to identify certain characteristics: 1) B67-SAT often followed the course from transient thyrotoxicosis to a hypothyroid phase to a euthyroid phase [6 of 9 B67-SAT (67%) vs. 10 of 40 B35-SAT (25%); P < 0.05]; and 2) B67-SAT occurred mostly during the summer or autumn and at a higher rate than did B35-SAR [8 of 9 B67-SAT (89%) vs. 17 of 40 B35-SAT (43%)], whereas B35-SAT occurred throughout the year. We conclude that there are at least two types of SAT that can be classified by association with either HLA-B35 or HLA-B67 antigens.

Expression of c-Mpl and c-Mpl ligand gene in hematopoietic cells of individuals with and without myeloproliferative disorders and leukemia cell lines

We examined the expression of c-Mpl (MPL) and c-Mpl ligand (ML) gene in hematopoietic cells in individuals with and without myeloproliferative disorders (MPD) and leukemic cell lines by RT-PCR. The MPL gene transcripts were detected in normal CD34+ cells, platelets, megakaryocytes and monocytes, while the ML gene was expressed in CD34+ cells, megakaryocytes, T cells, monocytes and bone marrow fibroblasts, as well as liver tissue. The ML gene product produced in the bone marrow microenvironment might, in part, be involved in hematopoiesis. The MPL gene expression was detected in platelets and peripheral blood mononuclear cells from the majority of patients with MPD including chronic myelocytic leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). In contrast, the ML gene expression was found in the majority of ET and CML patients, but not in PV or PMF patients. These findings suggest that even in MPD the megakaryocytopoiesis depends on the MPL signal transduction system, and that in ET and CML, the ML production by mononuclear cells in the bone marrow microenvironment might play a part in the higher megakaryocytopoiesis observed in these diseases. Both the MPL and ML gene expression were detected in all the leukemic cell lines tested, suggesting that this cytokine/receptor system is involved in cell growth through autocrine and paracrine systems.

Differences in MHC class I self peptide repertoires among HLA-A2 subtypes

To investigate how single amino acid substitutions in MHC class I molecules affect differences in peptide repertoires, we eluted and sequenced the naturally processed peptides from three HLA-A2 subtypes (HLA-A*0204, -A*0206, and -A*0207) that differ by a single amino acid residue substitution each with HLA-A*0201 at the floor of the binding groove. Allele-specific peptide motifs for each HLA-A2 subtype substantially differed from that of HLA-A*0201 in the dominant anchor residues. The relative signal intensities for 18 self peptides, determined by mass spectrometry, precisely reflected these peptide motifs. Some overlapping peptides were isolated from both HLA-A*0201 and a single HLA-A2 variant, but no peptide was ubiquitously found across all variants. To rationalize the differences in peptide motifs, possible conformations of each allele were computer modeled by energy minimization calculations based on the reported crystal structure of HLA-A*0201. According to our models, the differences in peptide motifs could be explained by substituted-residue-driven conformational changes for each MHC-peptide complex. These results demonstrate the fine differences between HLA-A2 subtype self peptide repertoires and contribute to the prediction of antigenic peptides.

Differences in MHC class I self peptide repertoires among HLA-A2 subtypes

To investigate how single amino acid substitutions in MHC class I molecules affect differences in peptide repertoires, we eluted and sequenced the naturally processed peptides from three HLA-A2 subtypes (HLA-A*0204, -A*0206, and -A*0207) that differ by a single amino acid residue substitution each with HLA-A*0201 at the floor of the binding groove. Allele-specific peptide motifs for each HLA-A2 subtype substantially differed from that of HLA-A*0201 in the dominant anchor residues. The relative signal intensities for 18 self peptides, determined by mass spectrometry, precisely reflected these peptide motifs. Some overlapping peptides were isolated from both HLA-A*0201 and a single HLA-A2 variant, but no peptide was ubiquitously found across all variants. To rationalize the differences in peptide motifs, possible conformations of each allele were computer modeled by energy minimization calculations based on the reported crystal structure of HLA-A*0201. According to our models, the differences in peptide motifs could be explained by substituted-residue-driven conformational changes for each MHC-peptide complex. These results demonstrate the fine differences between HLA-A2 subtype self peptide repertoires and contribute to the prediction of antigenic peptides.

Closure of the distal pancreatic stump with a seromuscular flap

We describe herein our new method for transecting the pancreas and closing its stump in distal pancreatectomy, devised to decrease the risk of pancreatic fistula formation. With this technique, the pancreas is transected in such a way that a convex stump is left, whereby the pancreatic secretions from the parenchyma near the pancreatic stump are fully drained into the main pancreatic duct. A pedicled seromuscular flap of the stomach or jejunum is then used to cover the cut surface of the pancreas. This new technique provides tight closure of the pancreatic stump after distal pancreatectomy.

c-kit point mutation of extracellular domain in patients with myeloproliferative disorders

c-kit is a tyrosine kinase receptor whose ligand is stem cell factor (SCF). Gene alteration of the c-kit extracellular domain was analysed by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) in 25 patients with myeloproliferative disorders (MPD). In the N-terminal part of the domain, mobility shifts indicating sequence alteration were detected in three of the patients, two primary myelofibrosis (PMF) and one chronic myelogenous leukaemia (CML). The subsequent sequencing revealed the same point mutations at codon 52 causing amino acid substitution (Asp-->Asn). To our knowledge this is the first report with a c-kit point mutation found in human fresh tumour cells.

Leukemic transformation of primary myelofibrosis: immunophenotype, genotype and growth characteristics of blast cells

Blast cells from six patients with leukemic transformation of primary myelofibrosis (PMF) were studied by morphology, immunophenotype and genotype as well as response to hematopoietic growth factors. The majority of the patients showed granulocytic or granulo-monocytic blasts, and only one had T lymphoid-monocytic blasts. None of the patients showed rearrangement of Ig or TCR genes, or the existence of the bcr-abl fused gene. A prominent growth response to GM-CSF and IL-3 was evident in all of the patients examined in liquid as well as semisolid cultures. The response to G-CSF was observed in four of the six patients in suspension culture, and in two of three patients in the clonogenic assay. Stem cell factor (SCF) was a weak growth stimulant, however the combination of this factor with GM-CSF or IL-3 was synergistically stimulatory. These results suggest that leukemic transformation of PMF occurs mainly at the level of myeloid stem cell, and that GM-CSF, IL-3, G-CSF and SCF are major growth factors for the blast cells in these cases.

Graded exercise in three cases of heart rupture after acute myocardial infarction

Despite advances in the study of exercise for acute myocardial infarction (AMI) patients, few studies on exercise for post-AMI heart rupture patients have been reported. We assessed three cases of heart rupture (of the left ventricular free wall in two cases and of the ventricular septum in one case) in post-AMI patients who underwent three-graded exercise. Two of the three patients were operated on, whereas one patient was managed conservatively for heart rupture. Two of the three cases had also suffered cerebral infarction post-AMI. The exercise program was composed of three grades, slow level walking (grade 1), mild reconditioning and activities of daily living (ADL) exercises (grade 2), and optional endurance training using machines below 75% of predicted maximal heart rate (grade 3). Electrocardiograms and blood pressure were monitored during all exercises. All patients had muscle weakness, poor endurance capacity, as well as low cardiac function (28-47% of left ventricular ejection fraction). Two patients underwent grades 1 and 2 exercise programs, and the other performed grades 1, 2, and 3 exercise programs over a 3- to 10-wk period. We observed improvement in the double product, work capacity, and ADL without congestive heart failure, ischemic attack, or serious arrhythmias. However, the youngest patient, who underwent the grade 3 exercise program, died from a cardiac event 10 mo after onset of AMI. We conclude that post-AMI heart rupture patients should undergo delayed, gradual, low-level graded exercise (4-6 metabolic equivalents), with monitoring of blood pressure and electrocardiograms to improve work capacity, ADL, and the quality of life. However, daily activity and exercise intensity should be promptly supervised for those with severely deteriorated cardiac functions to prevent sudden cardiac event.

HLA-linked susceptibility and resistance genes in Crohn's disease

BACKGROUND & AIMS

Previous studies have shown a positive association of HLA-DR4-DQ4 with Crohn's disease in the Japanese population, but the association between Crohn's disease and HLA genes has yet to be fully elucidated. The aim of this study was to determine the Crohn's disease/HLA association using a DNA typing method.

METHODS

A total of 90 unrelated patients with Crohn's disease and 336 healthy controls were typed for HLA class II genes including DP using DNA typing with the polymerase chain reaction-sequence-specific oligonucleotide probes method.

RESULTS

Allelic analysis showed that DRB1*0405, DRB1*0410, DQA1*03, DQB1*0401, and DQB1*0402 are positively associated and DRB1*1501, DRB1*1302, and DQB1*0602 negatively associated with Crohn's disease. DP genes showed no significant association with Crohn's disease. Haplotype analysis showed positive associations with DRB1*0405-DQA1*03-DQB1*0401, DRB1*0410-DQA1*03-DQB1* 0402, and DRB1*0802-DQA1*03-BQB1-0402 haplotypes and negative associations with DRB1*1501-DQA1*0102-DQB1*0602 and DRB1*1302-DQA1*0102-DQB1*0604 haplotypes.

CONCLUSIONS

In Crohn's disease in the Japanese population, the HLA-linked disease susceptibility gene is primarily associated with DQB1*04, in which leucine at the 56th position is a unique amino acid, and the disease resistance allele is suggested to be DQA1*0102.

DNA typing of HLA class II genes in Japanese patients with dilated cardiomyopathy

HLA class II genes (DRB, DQA, DQB, DPA, and DPB) were typed at the DNA level using polymerase chain reaction/sequence-specific oligonucleotide probe analysis in 78 unrelated patients with DCM and 336 unrelated healthy controls to elucidate the HLA alleles or HLA haplotypes associated with DCM. The frequencies of DRB1*1401 (15.4% v 4.5%, RR = 3.90, P < 0.0005, Pc < 0.03), DQB1*0503 (14.1% v 5.4%, RR = 2.93, P < 0.007) and DRB1*1401-DQB1*0503 haplotype (11.5% v 1.5%, RR = 8.24, P < 0.00001, Pc < 0.01) were increased in the DCM patients. The frequency of HLA-DRB1*1101 (9.0% v 3.0%, RR = 3.26, P < 0.02) also was increased in the patients. In addition, the frequencies of DQB1*0604 and DPB1*0401 were increased in the DRB1*1401 and DRB1*1101 negative patients. In contrast, the frequencies of DQB1*0303 (19.2% v 30.7%, RR = 0.55, P < 0.05) and DRB1*0901-DQB1*0303 haplotype (16.7% v 29.8%, RR = 0.49, P < 0.02) were decreased in the DCM group. Disease susceptibility to DCM in the Japanese population, thus, may be controlled in part by a gene (or genes) in close linkage disequilibrium with DRB1*1401-DQB1*0503, DRB1*1101-DQB1*0301, and DQB1*0604-DPB1*0401 haplotypes, while the resistance to DCM may be associated with the DRB1*0901-DQB1*0303 haplotype.

Profile of urinary bile acids in familial intrahepatic cholestasis with Coombs' negative haemolytic anaemia

We present two male siblings with intrahepatic cholestasis and prolonged indirect hyperbilirubinaemia. Their familial intrahepatic cholestasis syndrome was characterized by Coombs' negative haemolytic anaemia, without giant cell transformation of hepatocytes and high concentrations of serum gamma-glutamyl transpeptidase and cholesterol. By gas chromatography-mass spectrometry, we detected large amounts of 1 beta-hydroxylated bile acids, especially 1 beta,3 alpha,7 alpha,12 alpha-tetrahydroxy-5 beta-cholan-24-oic acid (25.5-67.9% of total urine bile acids) in the urine during phenobarbital therapy. However, the amount of urinary 1 beta-hydroxylated bile acids gradually decreased as the disease progressed. At the end-stage, we detected large amounts of 7 alpha,12 alpha-dihydroxy-3-oxochol-4-en-24-oic acid (19.6% of total urine bile acids). The ratio of 7 alpha,12 alpha-dihydroxy-3-oxochol-4-en-24-oic acid to cholic acid in the urine was 0.8. We conclude that in infants with end-stage liver failure, the microsomal hydroxylation of bile acids is impaired and the excretion of delta 4-3-oxo bile acids is increased.

HLA A2601-restricted CTLs recognize a peptide antigen expressed on squamous cell carcinoma

The CD4-CD8+ CTL (KE-4 CTL) cell line against autologous tumor cells was established in a patient with esophageal cancer. This KE-4 CTL recognized a peptide antigen on esophageal and lung squamous cell carcinomas in an HLA A2601-restricted manner, as evaluated by cytotoxicity against a panel of tumor cells, transfection experiments with HLA A2601 cDNA, and reconstitution with eluted peptides. None of the normal cells tested was lysed by this CTL. These results suggest the existence of HLA A2601-restricted CTL precursors recognizing a peptide antigen on SCC in a patient with esophageal cancer.

DQCAR microsatellite polymorphisms in three selected HLA class II-associated diseases

DQCAR is a very polymorphic CA repeat microsatellite located between the HLA DQA1 and DQB1 gene. Previous studies have shown that specific DQCAR alleles are in tight linkage disequilibrium with known HLA DR-DQ haplotypes. Of special interest was the fact that haplotypes containing long CA repeat alleles (DQCAR > 111) were generally more polymorphic within and across ethnic groups. In these latter cases, several DQCAR alleles were found even in haplotypes containing the same flanking DQA1 and DQB1 alleles. In this work, three HLA class II associated diseases were studied using the DQCAR microsatellite. The aim of this study was to test if DQCAR typing could distinguish haplotypes with the same DRB1, DQA1 and DQB1 alleles in control and affected individuals. To do so, patients with selected HLA DR-DQ susceptibility haplotypes were compared with HLA DR and DQ matched controls. This included: Norwegian subjects with Celiac disease and the HLA DRB1*0301, DQA1*05011, DQB1*02 haplotype; Japanese subjects with Type 1 (insulin-dependent) Diabetes Mellitus and the HLA DRB1*0405, DQA1*0302, DQB1*0401 haplotype; and French patients with corticosensitive Idiopathic Nephrotic Syndrome and the HLA DRB1*0701, DQA1*0201, DQB1*0202 haplotype. These specific haplotypes were selected from our earlier work to include one haplotype bearing a short DQCAR allele (celiac disease and DR3,DQ2-DQCAR99) and two haplotypes bearing long DQCAR alleles (Diabetes Mellitus and DR4,DQ4-DQCAR 113 or 115 Idiopathic Nephrotic syndrome and DR7,DQ2-DQCAR 111-121). Additional DQCAR diversity was found in both control and patients bearing haplotypes with long CA repeat alleles. The results indicate that DQCAR typing did not improve specificity in combination with high resolution DNA HLA typing as a marker for these three disorders.

Molecular cloning and nucleotide sequence of purine nucleoside phosphorylase and uridine phosphorylase genes from Klebsiella sp

Klebsiella sp. LF 1202 was isolated as a bacterium that can assimilate adenosine as a sole source of carbon and nitrogen [F. Ling et al., Agric. Biol. Chem., 55, 573-575 (1991)] from a soil sample. Both the purine nucleoside phosphorylase (PNPase) and uridine phosphorylase (UPase) of this bacterium were induced simultaneously when the bacterium was cultured in a medium containing adenosine or uridine as a sole source of carbon and nitrogen. This induction profile is different from that of Escherichia coli. Here we cloned and sequenced the gene corresponding to each enzyme. The open reading frame (ORF) of the PNPase gene consisted of 717 bp that encoded a polypeptide of 239 amino acids with a molecular weight of 26,198. The ORF of the UPase gene consisted of 834 bp that encoded a polypeptide of 278 amino acids with a molecular weight of 28,912.

Synthesis of 19-hydroxylated bile acids and identification of 3 alpha,7 alpha,12 alpha,19-tetrahydroxy-5 beta-cholan-24-oic acid in human neonatal urine

The synthesis of 19-hydroxylated bile acids (3 alpha,19-dihydroxy-, 3 alpha,7 alpha,19-trihydroxy-, 3 alpha,12 alpha,19-trihydroxy- and 3 alpha,7 alpha,12 alpha,19-tetrahydroxy-5 beta-cholan-24-oic acids) was described. These synthesized 19-hydroxylated bile acids were used as standard samples for the analysis of bile acids in human urine by gas chromatography-mass spectrometry. 3 alpha,7 alpha,12 alpha,19-Tetrahydroxy-5 beta-cholan-24-oic acid was identified in neonatal urines (0.1-1.5 micrograms/ml and 1.5-7% of total bile acids).

Accuracy of prostatic volume calculation in transrectal ultrasonography

BACKGROUND

Estimation of the prostatic volume by transrectal ultrasonography is now widely used to evaluate the effect of conservative treatment and to improve the specificity of prostate specific antigen. Accurate measurement of prostatic volume is necessary for the calculation of prostate specific antigen density (PSA/prostatic volume ratio).

METHODS

Three dimensional models of the prostatic contour were constructed from transrectal ultrasonotomograms taken at 5 mm intervals in 20 cases. Using these models, the accuracy of ellipsoid volume calculation and prolate ellipse volume calculation were examined. For prolate ellipse volume calculation, prostatic length was measured in two ways; length (Lv) vertical to the transverse section, and length (Lp) parallel to the prostatic urethra.

RESULTS

Ellipsoid volume calculation showed errors of about 20%. Moreover, ellipsoid volume calculation fluctuated markedly (up to 50%) in accordance with the change of the scanning angle of the transverse section. The error of prolate ellipse volume calculation using Lp for length increased by an average of 25% as the angle moved away from the perpendicular. The prolate ellipse volume calculation using Lv for length was the most reliable method. The degree of error was least dependent on the angle between the plane and the axis.

CONCLUSION

Although prolate ellipse volume calculation was more accurate than ellipsoid volume calculation, it is essential to have the three axes cross at right angles to obtain an accurate value by the prolate ellipse volume calculation.

Hippocampal homosynaptic long-term depression/depotentiation induced by adrenal steroids

The effects of adrenal steroids on synaptic plasticity were investigated in the dentate gyrus of the hippocampus. Experiments were performed in either adrenalectomized or intact (non-adrenalectomized), anesthetized rats. High-frequency stimulation was applied to the medial perforant pathway at three different frequencies; 100, 200 or 400 Hz, either post- or pre- and post-administration of the specific Type-II adrenal steroid receptor agonist RU 28362. High-frequency stimulation prior to RU 28362 administration produced a frequency-dependent long-term potentiation of the population spike, with 100 Hz showing no long-term potentiation and 400 Hz the highest degree of potentiation. In contrast, following administration of RU 28362, high-frequency stimulation produced a long-term depression (in comparison to baseline). In the experiments in which high-frequency stimulation was applied both pre- and post-RU 28362 administration, the size of the population spike was initially potentiated and then depotentiated after the RU 28362 injection. This effect was also frequency dependent, although opposite to the long-term potentiation effect. That is, 400 Hz was the least effective frequency for inducing long-term depression/depotentiation, while 100 Hz was the most effective. Long-term depression/depotentiation was immediate following high-frequency stimulation and lasted for the extent of the recording session, in some cases longer than 1 h. Similar to the finding reported in the accompanying paper, induction of long-term potentiation was substantially suppressed by RU 28362. However, in a number of experiments long-term potentiation could still be induced after RU 28362 administration, even after long-term depression/depotentiation had been established. In these cases, stimulation at the higher frequencies was necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Direct in vivo observation of subendocardial arteriolar response during reactive hyperemia

To study the vasodilatory capacity of subendocardial (ENDO) arterioles, we evaluated the reactive hyperemic responses of ENDO as well as subepicardial (EPI) arterioles in 40 dogs by our needle-probe intravital microscope. We also examined the individual and combined effects of an ATP-sensitive K+ channel blocker (glibenclamide, 200 micrograms/kg), an inhibitor of nitric oxide synthase (NG-monomethyl-L-arginine [L-NMMA], 2 mumol/min, 20 minutes), and an adenosine-receptor antagonist (8-phenyltheophylline [8PT], 0.75 mumol/min, 15 minutes). The percent increase in end-diastolic diameter of ENDO arterioles was larger (P < .01) than that of EPI arterioles during reactive hyperemia, especially for the arterioles larger than 120 microns (P < .01). The diastolic-to-systolic vascular pulsation amplitude at the peak flow was greater in ENDO than EPI arterioles (25% versus 6%, P < .05). Compared with control conditions, the presence of both glibenclamide and L-NMMA suppressed the vasodilation responses of ENDO arterioles (P < .01 for both) and EPI arterioles (P < .05 for both). The effect of L-NMMA was greater in ENDO arterioles (P < .01), but that of glibenclamide was not different between ENDO and EPI arterioles. 8PT influenced the hyperemic response, although statistical significance was found only in the flow response. The effect of combined infusion of L-NMMA and glibenclamide with or without 8PT was greater than that of individual infusions in both ENDO and EPI arterioles. Conclusions are as follows: (1) The vasodilatory response of ENDO arterioles was even larger than that of EPI arterioles. Thus, the smaller flow reserve of ENDO arterioles may be caused by other factors, including the greater effects of myocardial compression and nitric oxide on the ENDO arterioles. (2) The vascular responses of ENDO and EPI arterioles were modulated by both endothelium-independent and -dependent vasodilative factors, and the effect of each factor including adenosine was associated with the effects of others.

Relation between macro-EMG and muscle Uber conduction velocity

We investigated the relationship between macro-EMG and muscle Uber conduction velocity in the right biceps brachii in 5 normal subjects using a single-Uber macroelectrode and surface array electrodes. The macro-EMG signal and the surface electrode signals were triggered and averaged by the single-Uber action potential. The amplitude and area of the macro-EMG was correlated with the muscle Uber conduction velocity, suggesting that the macro-EMG can serve as a parameter of the size principle in both the clinical and research settings.

[Pharmacokinetic investigation of 5-day multiple dose of tropisetron capsule in patients who had received cisplatin and the usefulness of tropisetron capsule in the treatment of nausea and vomiting]

We have investigated the pharmacokinetics of a 5-day multiple oral dose of 5 mg tropisetron capsule in patients with malignant tumour who had received cisplatin single administration. Its anti-emetic effects on acute and delayed emesis and vomiting were also investigated. During the 5 days after this administration, changes in the release and metabolism of serotonin were investigated. The results may be summarized as follows: 1) The pharmacokinetic parameters of tropisetron revealed no significant change in the data between day 1 and day 5. Also, the parameters were almost similar to those observed in healthy adult males (clinical phase I study); Cmax. T1/2 and AUC 0-24 hrs on day 1 were 9.1 +/- 2.1 ng/ml, 12.5 +/- 4.2 hrs, 85.5 +/- 22.7 ng.hr/ml, respectively. The urinary excretion of the parent drug up until 24 hours after administration on day 1 was 3.8% of the dose administered and 2.9% of the total dose after the last administration; no difference in the urinary excretion rate was observed in healthy subjects. It was thus suggested that hydration accompanied by cisplatin administration did not affect the pharmacokinetics of tropisetron. 2) The changes in the amount of urinary excretion of 5-hydroxy-indoleacetic acid (5-HIAA) during 5 days after cisplatin administration were observed; urinary excretion of 5-HIAA increased 2.3 times (1.3-5.4 times) the baseline on the average during 6 to 12 hours on day 1. In 6 out of 10 patients, the increases in urinary excretion of 5-HIAA showed double or more the baseline during 2 to 5 days after cisplatin administration. Serotonin was thus deemed to be related to the development of delayed emesis. 3) The anti-emetic effects of tropisetron on acute and delayed emesis and vomiting were rated as "markedly effective" in 6 out of 11 patients (54.6%) and "effective" in 1 out of 11 patients (9.1%) on day 1; vomiting did not occur in any of these 7 patients. Tropisetron also controlled emesis and vomiting during days 2-5, and was rated as "almost favorable" in 6 out of 11 patients (54.5%). Further, in 4 out of 6 patients, in whom the urinary excretion of 5-HIAA was increased on day 2 onwards, vomiting did not occur during the time when the urinary excretion of 5-HIAA was increasing. On the basis of the above results, tropisetron is deemed to have certain antiemetic effects on delayed vomiting as well. Its 5-HT3 receptor mediated mechanism was similarly seen to inhibit acute nausea and vomiting.