Purification and characterization of thrombopoietin

A thrombopoietic factor, termed thrombopoietin (TPO), was highly purified directly from the plasma of sublethally irradiated 1,100 rats by measuring the production of megakaryocytes from a highly enriched population of rat megakaryocyte progenitor cells (CFU-MK). The rat plasma TPO is a glycoprotein and strongly hydrophobic. The total activity and purification yields obtained were about 29% and 1.49 x 10(8), respectively. The amino acid sequences of the two peptide fragments prepared from the purified 19 kDa TPO were analyzed, and used for the cloning of rat and human TPO cDNAs. It was found that the 19 kDa TPO was truncated but comprised at least 163 amino acids. The sequence of human TPO cDNA revealed that the TPO was identical to the c-Mpl ligand. Both rat and human TPOs expressed in COS-1 cells exhibited significant activity toward the CFU-MK in vitro, and were active in stimulating platelet production in mice. These results indicate that a thrombopoietic factor originally found in the irradiated rat plasma is a ligand for the rat c-Mpl.

[Screening program with urinary porphyrins--application to clinical finding in latent porphyrias]

Judging from the incidence of porphyria in Japan, most cases can be diagnosed by measurement of the amount of porphyrin in the urine. Normally, the analysis of porphyrin in urine is performed by high-performance liquid chromatography but this requires about 40 minutes per specimen. However, if one simply measures coproporphyrin I and III only, then one specimen can be measured in about 10 minutes. If screening is performed using this method, those subjects in which high levels of coproporphyrin I and III are detected can undergo further test of urine, blood and feces to detect porphyrin and related materials. Using this screening methods in high school students, 2 cases of congenital porphyria were detected. One case was hereditary coproporphyria and the other was acute intermittent porphyria. If this method is added to screening methods normally used for health checkups, cases of porphyria should be detected with ease.

[Secondary tumor of the temporal bone with internal auditory meatus involvement--histopathological study]

Nineteen cases of secondary tumor of the temporal bone with involvement of the internal auditory meatus (IAM) were studied. The cases were classified into 4 invasion modes; direct extension from head and neck tumors (12 cases), hematological dissemination (3 cases), diffuse leptomeningeal carcinomatosis (3 cases), and direct extension of tumors from the intracranium (1 case). There were some differences in the manner in which the tumor had spread among these 4 modes. In most cases involving "direct extension from head and neck tumors", the tumor had invaded the pyramis, and then the Eustachian tube and the middle ear. When the inner ear or the IAM was involved, it was directly invaded by massive tumor. In all cases of "hematological dissemination", metastatic tumor was found bilaterally, but there were some differences in the manner of invasion between the two sides. In "leptomeningeal carcinomatosis" and "intracranial tumor", the tumor had invaded the temporal bone bilaterally via the IAM. In the IAM, cochlear and inferior vestibular nerves were more vulnerable to tumor invasion than facial and superior vestibular nerves. It was suggested that there are some differences in vulnerability to tumor invasion between the superior and inferior vestibular nerves. The bottom of the IAM presented a barrier-like effect against the spread of tumor from the IAM to the labyrinth. In some cases, however, there was massive tumor invasion of the internal ear directly from the IAM. Whether denervation of the ganglionic neurons (spiral or vestibular) causes secondary degeneration of peripheral sensory endorgans remains controversial. In some cases in our series, degeneration of the auditory or vestibular peripheral organs might be attributed to denervation of neurons in the spiral or vestibular ganglia. In other cases, however, auditory and vestibular peripheral organs remained intact despite severe degeneration of ganglionic neurons.

Simultaneous measurement of pulmonary diffusing capacity for CO and cardiac output by a rebreathing method in patients with pulmonary diseases

Pulmonary diffusing capacity for CO (DLCO) and cardiac output (Q) were simultaneously measured by a noninvasive rebreathing method (RB) in 15 normal subjects and in 60 patients, including cardiac diseases (CD), bronchial asthma (BA), chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (PF). DLCO and Q were tested by the single breath method (SB) and the dye-dilution method (Dye), respectively. DLCO (RB) correlated well with DLCO (SB) (r = 0.890, p < 0.001). Q(RB) also correlated well with Q(Dye) (r = 0.909, p < 0.001). Factors affecting DLCO (RB) were age, height, body surface area, O2 consumption, Q, hematocrit (Het) and Q.Hct, among which Q.Hct was the prominent influential determinant. DLCO per lung volume was smaller in COPD and PF than in BA or healthy subjects, while, the ratio of DLCO/(Q.Hct) was significantly higher in COPD than in PF. Simultaneous measurements of DLCO and Q offer comprehensive characterization for functional changes in lung parenchyma.

[Recent progress in development of psychotropic drugs (1)--Anti-anxiety drugs]

Anti-anxiety drugs are widely used for patients with neurosis or psychosomatic diseases due to the stress of contemporary society. The high efficacy of benzodiazepine (BZD) or its analog, which contains diazepam, is well-known. While these compounds have strong anti-anxiety effects, it has recently been pointed out that they have some side effects when used as daytime tranquilizers and induce drug dependence. The cause of these side effects is thought to be that typical BZD is a full agonist of BZD receptors. For this reason, partial agonists, inverse agonists and antagonists of BZD receptors are being developed. Furthermore, some non-BZD anti-anxiety drugs are also being developed to avoid the side effects of BZD. One of these is a 5-HT1A agonist, which has a high affinity for 5-HT receptors, because it is reported that 5-HT is related to anxiety in the septum-hippocampus system. In addition, the anti-anxiety effect of 5-HT3 agonist is being investigated, while the anti-anxiety effect of cholecystokinin agonists is also attracting attention. Because these new anti-anxiety drugs are more potent and have fewer side effects than BZD, they may achieve widespread clinical use.

[Two dimensional analysis of neural activities by calcium imaging]

The development of fluorescent Ca2+ indicators made us possible to measure the intracellular Ca2+ concentration easily. Furthermore the analysis of fluorescent images obtained by a fluorescence microscope became easy and popular, because of the tremendous development of computers and related hardwares. Time courses and topographical differences in Ca2+ concentration can be demonstrated as two dimensional color-coded images. Such images are sometimes quite persuasive. That is just "Seeing is believing". We can detect a completely new site of biological phenomena through this method. This article will describe many different types of Ca2+ indicators and applications to biological image analysis. Especially the method called "macro" image analysis can demonstrate the regional difference in changes of the Ca2+ concentration of slice preparation during medical treatment of cerebral ischemia. Already more than ten years have passed since the first demonstration of a fluorescent Ca2+ indicator, quin 2, and the methods using such Ca2+ indicators become important in the field of experimental biology.

[Protective effects of LipoPGE1, prostaglandin E1 incorporated in lipid microspheres, against liver injury caused by ischemia-reperfusion]

Effect of LipoPGE1 on liver injury caused by ischemia-reperfusion were compared with that of PGE1-CD, cyclodextrin clathrated PGE1, in rats. LipoPGE1 (10 micrograms/kg) and PGE1-CD (10 micrograms/kg) were gradually injected into the portal vein 5 min both prior to ischemia and prior to reperfusion. In only the group receiving injections of vehicle alone, rats died within 2 days after the episode of 90-min liver ischemia. The survival rate of all rats treated with LipoPGE1 was higher than that of rats who received vehicle alone, which indicates that LipoPGE1 pretherapy improved the survival of rats after liver ischemia-reperfusion. LipoPGE1 markedly suppressed elevations of GOT, GPT, and LDH, lipid peroxide and aromatic amino acid levels in the plasma caused by ischemia-reperfusion of the liver. When animals were given a single dose of LipoPGE1 prior to reperfusion, LipoPGE1 also suppressed elevations of GOT, GPT, LDH and lipid peroxide levels caused by 30-min of liver ischemia followed by 12-hr reperfusion. These suppressive effects with LipoPGE1 were stronger than those of PGE1-CD. These findings suggest that LipoPGE1 may have therapeutic applications in the treatment of hepatic injury.

Upstream and intron regulatory regions for expression of the rat neuron-specific enolase gene

Neuron-specific enolase (NSE) occurs in mature neurons and paraneurons. We have isolated the genomic clone coding for rat NSE and clarified its gene structure. In order to analyze the regulatory sequence in the 5'-upstream region and introns, we carried out transient expression experiments of NSE genomic DNA fragments fused to chloramphenicol acetyltransferase (CAT) gene which were transfected into several cultured cells. The used cells were primary cultured rat neurons, PC12, neuroblastoma 35, neuroblastoma 103, C6, primary cultured rat glial cells and HeLa cells. The promoter sequence (190 bp) upstream to the transcription initiation site was important in the expression of CAT gene in these cells. From the experiments with external and internal deletion mutants of the fusion gene, the cis-acting regulatory region responsible for the enhanced expression of the CAT activity in the primary cultured neuron and PC12 cells was found to be localized at upstream 500 bp sequence of the intron 1 and 1.5 kbp upstream sequence of the transcription initiation site. In the upstream important sequences, there were the nearest sequences for AP-1 binding motif, AP-2 binding element, SP-1 binding sequence, cAMP response element, half site of glucocorticoid receptor (GRE) binding sequence, half site of thyroid hormor receptor (TR) or retinoic acid receptor (RAR) binding sequence and MTF-1 binding sequence. Furthermore, Octamer-6 binding motifs also were found. In the intron 1, 5' end upstream 50 bp and downstream 100 bp were the most important sequences. We found the nearest sequences for cAMP response element, E2F binding sequence, early growth response (EGR)-1 binding motif, half site of TCF-1 binding sequence and a neuron-specific element-like sequence in the intron 1.

Ocular movement during reading in patients with congenital nystagmus

When a healthy person reads sentences arranged horizontally, the eye movement pattern is a series of regular saccades and rest periods. However, eye movements while patients with oculomotor disturbances are reading remain to be defined. In this study, 4 patients with congenital nystagmus (CN) were studied. Coordinated movements of eye and head are also studied by a new apparatus with terrestrial magnetism sensor. While subjects were reading, an eye movement pattern was superimposed by the CN waveform and showed few rest periods. Eye velocity of less than 4 degrees/s was noted in almost every cycle of the eye movements while the patients with CN were reading. When they were requested to read sentences and simultaneously rotate their head naturally, the head movements had the effect of cancelling the eye instability. This finding may be interpreted as a kind of "eye-head coordination".

Temperature-dependent Ca2+ mobilization induced by hypoxia-hypoglycemia in the monkey hippocampal slices

Mobilization of [Ca2+]i in the monkey hippocampal slices during transient hypoxia-hypoglycemia and KCl-induced depolarization was analyzed by microfluorometric imaging and anti-PIP2 immunohistochemistry. Hypoxia-hypoglycemia provoked the largest [Ca2+]i mobilization of CA-1 temperature-dependently whereas [Ca2+]i mobilization by KCl-induced depolarization occurred independent of the temperature in CA-2. Immunohistochemical analysis of the hippocampus after hypoxia-hypoglycemia showed an increased PIP2 staining preferentially in the perikarya of CA-1 neurons. These data suggest that release of Ca2+ from intracellular stores caused by PIP2 breakdown may induce elevated [Ca2+]i.

Implication that potassium flux and increase in intracellular calcium are necessary for the initiation of sperm motility in salmonid fishes

Flux of K+ and changes in intracellular Ca2+ in the sperm of salmonid fishes were measured with spectrophotometry, ion electrode, microscopic fluorometry, and radioisotope accumulation. Release of K+ occurred at the initiation of sperm motility which is induced by decrease in external K+ and the K+ efflux and sperm motility were inhibited by K+ channel blockers. Intracellular Ca2+ increased within a short period in K(+)-free condition, and the accumulation of 45Ca in sperm cells was higher in motile sperm than that in immotile sperm. The efflux of K+ and the increase in intracellular Ca2+ were suppressed when external K+ concentration increased, i.e., sperm remained immotile. These results suggest that efflux of K+ through K+ channel and subsequent increase in intracellular Ca2+ are prerequisite for the initiation of sperm motility.

Automated collection of conditioned medium from organotypically cultured brain slice

For the analysis of neural activity over a long period of time, the organotypic culture of mammalian brain slices provides excellent specimens. To effectively utilize the slice culture, we developed a device for automatic sampling of the culture medium. This device is a computer-controlled combination of a multichannel peristaltic pump to remove the media from the glass culture containers, a fraction collector designed to allow quick freezing of the samples, and a multichannel syringe pump to deliver new media to the containers. Using this device, substances released as results of neural activities can be collected at regular intervals over several days. We monitored the circadian release of arginine-vasopressin from cultured suprachiasmatic nuclei. We also monitored tonic releases of lactate dehydrogenase from cultured hippocampi phasically treated with an excitotoxin and from those transiently deprived of oxygen/glucose.

Hydroxyl group of Tyr13 is essential for the activity of omega-conotoxin GVIA, a peptide toxin for N-type calcium channel

A series of analogs of omega-conotoxin GVIA, a peptide neurotoxin having 27 amino acid residues with three disulfide bridges, were synthesized by replacing each amino acid residue except for Cys and Hyp with Ala. CD spectra were virtually identical between native and all of the analogs, indicating the overall conformations were not changed by the substitutions. The inhibitory effects of these analogs on 125I-omega-conotoxin GVIA binding to chick brain synaptic plasma membranes showed that replacement of Tyr13 with Ala drastically lowered the affinity of the toxin to the N-type Ca2+ channel. Substitution of Tyr13 with Phe also showed reduction of the affinity, indicating that the hydroxyl group of Tyr13 is critical for binding. Since Lys2 is also important for binding (Sato, K. Park, N.-G., Kohno, T. Maeda, T., Kim, J.-I., Kato, R., and Takahashi, M. (1993) Biochem. Biophys. Res. Commun. 194, 1292-1296), we propose a two-point binding model in which Tyr13 and Lys2 interact with specific amino acid residues of the Ca2+ channel through hydrogen bonding and ionic interaction, respectively.

[Detection of Aspergillus fumigatus DNA by polymerase chain reaction in the clinical samples from individuals with pulmonary aspergillosis]

Aspergillosis is a disastrous cause of mortality and morbidity in patients in an immunocompromised state and old lung tuberculosis. However, the diagnosis of aspergillosis remains unsettled. In the present study, we developed a test to detect the Aspergillus fumigatus DNA using polymerase chain reaction (PCR) in clinical samples including sputum and bronchial aspirations from the patients with aspergillosis. We selected 2 pairs of oligonucleotide primers and the DNA for the small subunit ribosomal RNA of aspergillus fumigatus and they were significantly amplified. Although isolation of Aspergillus DNA may reflect contamination and colonization without infection, no aspergillus DNA was found in sputum or bronchial aspirations from the patients with lung cancer or interstitial lung diseases except a case of pulmonary fibrosis associated with rheumatoid arthritis chronically received 20 mg of corticosteroid. There was a 100% correlation between the culture results and the nested PCR results in the patients with pulmonary aspergillosis. These findings indicate that PCR detection of aspergillus fumigatus might be valuable for the diagnosis of aspergillosis.

Endothelin-3 stimulates inositol 1,4,5-trisphosphate production and Ca2+ influx to produce biphasic dopamine release from rat striatal slices

1. Real-time monitoring of dopamine (DA) release from rat striatal slices demonstrated that endothelin (ET)-3 (0.1-10 microM) produced a biphasic DA release consisting of transient and sustained components. When extracellular Ca2+ was removed, the sustained but not transient response remarkably decreased. 2. ET-3 (1-10 microM) stimulated an increase in the intracellular Ca2+ concentration ([Ca(2+)]i), which also consisted of two components. The external Ca2+ depletion inhibited primarily the sustained component of the Ca2+ response to ET-3. 3. ET-3 increased inositol 1,4,5-trisphosphate (IP3) concentrations in striatal slices. This response peaked at 10 to 20 sec and returned to the basal level 2 min after stimulation, an event which was in good accord with a prompt and transient phase of both cytosolic Ca2+ activity and DA release evoked by ET-3. 4. Thus, ET-3 produces a transient and a sustained release of DA from striatal slices by stimulating intracellular Ca2+ mobilization via IP3 formation and extracellular Ca2+ influx, respectively.

Endothelin increased [Ca2+]i in cultured neurones and slices of rat hippocampus

We reported here the first evidence that endothelin (ET)-1 and ET-3 produced an increase in intracellular Ca2+ concentrations ([Ca2+]1), consisting of a transient and a sustained component, in cultured neurones and in slices of the rat hippocampus. In the neurones, the removal of Ca2+ or the addition of Cd2+ remarkably inhibited the ET-3-evoked sustained but not the transient response. The [Ca2+]i increased by ETs was observed in the dentate gyrus and in the vicinity of CA1 and CA3 pyramidal cell layer in the hippocampus, findings in good accord with regions where the glutamate receptor agonists have an elevated [Ca2+]i. The possible causal link between ETs and the increased [Ca2+]i in the development of hippocampal neuronal death is discussed.

Effect of methylprednisolone on plasma lipid peroxidation induced by lipopolysaccharide

The effects of methylprednisolone succinate (MP) on plasma lipid peroxidation, plasma SOD activity and superoxide production in polymorphonuclear leukocytes (PMNs) induced by lipopolysaccharide (LPS) were examined in rats in vivo and in vitro. In rats subjected to LPS treatment, plasma phosphatidylcholine hydroperoxide (PCOOH) levels significantly increased, and the plasma Cu,Zn-SOD activity decreased by about 75%. When rats were given 30 mg/kg of MP intravenously, MP suppressed the elevation of plasma PCOOH levels and partially inhibited the decrease in plasma Cu,Zn-SOD activity. MP also suppressed PMA-induced superoxide production in PMNs primed by LPS. In in vitro experiments, low concentrations of MP had no effect on NADPH-dependent lipid peroxidation, but 4 mM MP produced 50% inhibition. MP had little effect on PMA-induced superoxide production in PMNs primed by LPS. Moreover, MP had no radical-trapping effect on superoxide, hydroxyl radical and stable DPPH radical. These results suggest that the suppressive effect of plasma lipid peroxidation by MP is not due to radical-trapping effects or preventive anti-oxidation, but may involve the suppression of the lipid chain reaction in liver membrane resulting from PMA-induced superoxide anions generated by PMNs.

[Residential movement of persons with senile dementia within one year prior to death]

The purpose of this study was to clarify what factors were affecting the residential movement of persons with senile dementia, within one year prior to their death, and to find out ways to sustain the quality of life of the terminal period. We analyzed ninety-six cases of the members of the Association of Family Caring for the Demented Elderly, who died within the period from 1989 to 1991. 1. The average age of death of the elderly persons was 83.2 years. Seventy-four percent had severe dementia. Fifty-five percent had complications of cancer, cardiopathy or apoplexy. 2. Thirty-three percent of the patients in the analyzed cases died at home, sixty percent died in hospitals, and seven percent died elsewhere. Only a few had been hospitalized for more than one year. 3. There were four major movement patterns: care at home and death at home, periodic hospitalization before death at home, periodic hospitalization before death at hospital, and hospitalization and death at hospital. Each of the four patterns had unique characteristics regarding both physical and mental disorders. 4. Those persons with periodic hospitalization before death at home had more care in regards to discharge guidance than those with periodic hospitalization before death at hospital. From the above analysis, we concluded that persons with senile dementia in their terminal period require preventative treatments against advanced dementia and the various complications. In addition they need effective discharge planning at medical institutions.

Regulation and physiological role of insulin-like-growth-factor-binding protein-1 in human granulosa cells

The present study was undertaken to elucidate the physiological role and the regulation of insulin-like growth factor (IGF)-binding protein-1 (IGFBP-1) in human luteinizing granulosa cells. IGFBP-1 abolished IGF-I-stimulated estradiol production by luteinizing granulosa cells in a dose-dependent manner with a 50% inhibitory concentration (IC50) of 0.27 nM. Similarly, IGFBP-1 inhibited 125I-IGF-I binding to granulosa cells. IGFBP-1 was identified by Western immunoblot and specific enzyme immunoassay in the granulosa-cell-conditioned medium after 24 h culture. Immunoreactive IGFBP-1 released into the medium was inhibited by both IGF-I and follicle-stimulating hormone dose-dependently with an IC50 of 0.14 and 0.13 nM, respectively, while human chorionic gonadotropin-stimulated IGFBP-1 release with a 50% effective dose (ED50) of 0.6 nM. These results suggest that IGFBP-1 is involved in follicular development and granulosa cell differentiation in the human ovary and that gonadotropins may influence IGF-I action by modifying IGFBP-1 levels within the ovary.

Effects of anti-free radical interventions on phosphatidylcholine hydroperoxide in plasma after ischemia-reperfusion in the liver of rats

The present study set out to investigate whether plasma phosphatidylcholine hydroperoxide (PCOOH) levels could accurately reflect lipid peroxidation linking to liver damage due to ischemia--reperfusion. PCOOH is a primary peroxidative product of phosphatidylcholine (PC), which is the most important functional lipid in the hepatocellular membrane, and may mediate oxidative stress. We quantified PCOOH and PC in the plasma and liver of rats subjected to hepatic ischemia-reperfusion by chemiluminescence detecting HPLC (CL-HPLC) method. Plasma PCOOH levels showed no significant rise in either the ischemia only group or in the sham-operation group, compared to controls (0.7 nmol/mL plasma). At 60 min subsequent to reperfusion, the PCOOH levels in plasma and liver, as well as the levels of several serum markers of liver injury [lactic dehydrogenase (LDH), glutamic-oxalacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT)] increased in proportion to the duration of ischemia (up to 60 min). During periods of reperfusion following 30 min of ischemia, plasma PCOOH increased biphasically (2 nmol/mL; 12-24 hr duration of reperfusion), and generally ran parallel to that in the liver after more than 60 min of reperfusion. Dose-dependent protective effects against warm ischemia (30 min)-reperfusion (12 hr) injury were clearly demonstrated in the groups treated with allopurinol, diclofenac Na, ascorbic acid (V.C), alpha-tocopherol and coenzyme Q10, but not in those treated with r-h-superoxide dismutase or betamethasone. The rises in plasma PCOOH and serum GOT, GPT and LDH of the ischemia-reperfused rats were ameliorated most in the group pretreated with diclofenac Na, and next most in the group pretreated with V.C. These results indicate that the plasma PCOOH levels are a useful index both for liver cell damage induced by oxygen free radicals generated during ischemia-reperfusion, and to investigate the efficacy of drugs against oxidative stress.

Early mobilization of Ca2+ is not required for glucocorticoid-induced apoptosis in thymocytes

Contradictory results have been reported on the question of the role of Ca2+ in glucocorticoid-induced apoptosis in thymocytes. To resolve this problem, we investigated the effect of dexamethasone, a synthetic glucocorticoid, on intracellular Ca2+ concentration ([Ca2+]i), by microscopic fluorometry that enables us to monitor real-time [Ca2+]i of cells loaded with fura-2, a fluorescent Ca2+ indicator, on a single cell basis. The results indicated that dexamethasone does not induce an increase in [Ca2+]i above control level both in murine and rat thymocytes at least for 1 h after the start of the culture. We also investigated whether the depletion of extracellular Ca2+ with EGTA or buffering intracellular Ca2+ with quin-2/AM inhibited glucocorticoid-induced apoptosis as reported on rat thymocytes. Dexamethasone-induced apoptosis in both murine and rat thymocytes, however, was not inhibited by EGTA. High concentrations (25 microM and over) of quin-2/AM inhibited DNA fragmentation, but failed to inhibit cytolysis. Calmodulin inhibitors, trifluoperazine and calmidazolium, also inhibited DNA fragmentation as reported, although they markedly enhanced cytolysis. Therefore, glucocorticoid-induced death is not inhibited by quin-2/AM or calmodulin inhibitors. Furthermore, we have previously found that a proper combination of the calcium ionophore, ionomycin, and the protein kinase activator, PMA, inhibits corticosterone-induced apoptosis. These results suggest that an early increase in [Ca2+]i is neither induced by glucocorticoids nor responsible for glucocorticoid-induced apoptosis in thymocytes.