Influence of extracorporeal porcine liver perfusion on nonhuman primates: minimizing hemolysis improves subsequent survival

The aim of this study is to detect and analyze risk factors of direct cross-circulation between porcine liver and nonhuman primates before a clinical application of extracorporeal liver perfusion (ECLP) as a liver-assist method. Porcine livers were perfused with baboon blood in an ECLP system. Six healthy baboons were directly connected to the ECLP system with continuous prostaglandin E(1) administration. Cross-circulation was terminated in the following circumstances: (1) hepatic arterial or portal perfusion pressures elevated to 200 or 60 mm Hg, respectively; (2) massive exudative bleeding from the graft surface; or (3) bile output decreased to less than 5 microL/h/g of liver weight. In case 1, cross-circulation was continued for 10 hours. Severe macroscopic hemolysis occurred, and serum hemoglobin (s-Hb) concentration reached a peak of 47 mg/dL. The baboon died of acute renal failure 2 days later. Histological study of the perfused porcine liver showed marked microthrombi formation. In 3 of the later 5 cases, cross-circulation was discontinued when mild macroscopic hemolysis was observed. The duration of the 5 cross-circulations was maximally 6 hours (mean, 4.4 +/- 1.2 [SD] hours). Mean s-Hb concentration in the 5 cases was elevated to 14.8 +/- 5.8 mg/dL at the end of cross-circulation and decreased to the baseline level within 24 hours. These 5 baboons survived without organ dysfunction or immunologic disturbance. When severe hemolysis is avoided, direct cross-circulation using the ECLP system can be achieved without serious complications in nonhuman primates.

Cellular mechanism of action of cognitive enhancers: effects of nefiracetam on neuronal Ca2+ channels

Cellular mechanisms underlying the cognition-enhancing actions of piracetam-like nootropics were studied by recording Ca2+ channel currents from neuroblastoma x glioma hybrid (NG108-15) cells and Xenopus oocytes expressing Ca2+ channels. In NG108-15 cells, nefiracetam (1 microM) produced a twofold increase in L-type Ca2+ channel currents. A similar, but slightly less potent effect was observed with aniracetam, whereas piracetam and oxiracetam exerted no such effects. Cyclic AMP analogs mimicked the nefiracetam action. N-type Ca2+ channel currents inhibited by leucine (Leu)-enkephalin by means of inhibitory G proteins (Go/Gi) were recovered promptly by nefiracetam, whereas those inhibited by prostaglandin E1 via stimulatory G proteins were not affected by nefiracetam. Cells treated with pertussis toxin (500 ng/mL, > 20 hours) were insensitive to nefiracetam. In Xenopus oocytes functionally expressing N-type (alpha1B) Ca2+ channels and delta-opioid receptors, nefiracetam was also effective in facilitating the recovery from Leu-enkephalin-induced inhibition. These results suggest that nefiracetam, and possibly aniracetam, may activate N- and L-type Ca2+ channels in a differential way depending on how they recover from Go/Gi-mediated inhibition.

Presynaptic nicotinic acetylcholine receptors as a functional target of nefiracetam in inducing a long-lasting facilitation of hippocampal neurotransmission

Nefiracetam (1-10 microM), a nootropic (or cognition-enhancing) agent, persistently potentiated currents through Torpedo acetylcholine (ACh) receptors expressed in Xenopus oocytes as a result of interacting with a protein kinase C pathway and the ensuing protein kinase C phosphorylation of the receptors. A similar effect was found in neuronal nicotinic ACh receptors (alpha4beta2 and alpha7). In contrast, the other nootropic agents such as piracetam and aniracetam had no potentiating action on the receptors. A sustained enhancement in the activity of nicotinic ACh receptors induced by nefiracetam caused a marked increase in the glutamate release, leading to a long-term potentiation-like facilitation of hippocampal synaptic transmissions. One of the consistent neuropathologic features of the Alzheimer brain is a loss of nicotinic ACh receptors. This fact, together with the results of our study, raises the possibility that the loss of nicotinic ACh receptors may be a key factor in the decline of cognitive function observed in Alzheimer disease and that agents targeting neuronal nicotinic ACh receptors like nefiracetam could, therefore, be of great therapeutic importance.

Attenuation of the development of morphine dependence/tolerance by nefiracetam: involvement of adenosine 3':5'-cyclic monophosphate system

Biochemical changes such as intracellular cAMP and Ca(2+) underlying morphine dependence and tolerance have been suggested. Therefore, we investigated the effects of nefiracetam (N-(2, 6-dimethyl-phenyl)-2(2-oxo-1-pyrrolidinyl) acetamide), which increases intracellular cAMP and Ca(2+) levels, on the development of morphine dependence and tolerance. Mice administered morphine (6 or 20 mg kg(-1)) twice daily for 5 days, showed withdrawal symptoms (jumping, diarrhea and body weight loss) after naloxone challenge (5 mg kg(-1)), indicating morphine dependence. Furthermore, tolerance to the analgesic effect of morphine was observed in these mice. Co-administration of nefiracetam (5 or 10 mg kg(-1)) with morphine during the pretreatment period, significantly reduced the signs of withdrawal symptoms, moreover, the tolerance was significantly attenuated. Elevation of cAMP levels in the cortex was observed in morphine-dependent mice, but not in mice co-administered nefiracetam. Acute administration of nefiracetam shows no effect on the withdrawal symptoms and the analgesic effect in morphine-naive mice. Theophylline (3 or 10 mg kg(-1)) tended to attenuate and enprofylline (10 or 30 mg kg(-1)) significantly attenuated the development of morphine dependence and tolerance. These findings suggest that co-administration of nefiracetam or compounds, which increase the cAMP level, may be a useful strategy for attenuating the development of morphine dependence and tolerance in the clinic.

The anti-dementia drug nefiracetam facilitates hippocampal synaptic transmission by functionally targeting presynaptic nicotinic ACh receptors

Nefiracetam, a pyrrolidone derivative developed as an anti-dementia drug, persistently potentiated currents through neuronal nicotinic acetylcholine (ACh) receptors (alpha7, alpha4beta2) expressed in Xenopus oocytes, and the potentiation was blocked by either the selective protein kinase C (PKC) inhibitors, GF109203X and staurosporine, or co-expressed active PKC inhibitor peptide. In primary cultures of rat hippocampal neurons, nefiracetam increased the rate of nicotine-sensitive miniature excitatory postsynaptic currents, without affecting the amplitude, and the increase was inhibited by GF109203X. In addition, the drug caused a marked increase in the glutamate release from electrically stimulated guinea pig hippocampal slices, and the effect was abolished by the nicotinic ACh receptor antagonists, alpha-bungarotoxin and mecamylamine. Nefiracetam induced a long-lasting facilitation of synaptic transmission in both the CA1 area and the dentate gyrus of rat hippocampal slices, and the facilitation was inhibited by alpha-bungarotoxin and mecamylamine. Such facilitatory action was still found in the hippocampus with selective cholinergic denervation. The results of the present study, thus, suggest that nefiracetam enhances activity of nicotinic ACh receptors by interacting with a PKC pathway, thereby increasing glutamate release from presynaptic terminals, and then leading to a sustained facilitation of hippocampal neurotransmission. This may represent a cellular mechanism underlying the cognition-enhancing action of nefiracetam. The results also provide the possibility that nefiracetam could be developed as a promising therapeutic drug for senile dementia or Alzheimer's disease.

Anticonvulsant actions of nefiracetam on epileptic EL mice and their relation to peripheral-type benzodiazepine receptors

Anticonvulsant actions of the nootropic drug nefiracetam were studied using EL mice, an animal model of epilepsy, in which peripheral-type benzodiazepine receptors (PBRs) might be involved in their epileptogenesis. Nefiracetam, when administered orally t o EL mice, inhibited convulsions induced by the PBR agonist, Ro 5-4864, with an ED(50) of 17.2 mg/kg, whereas it did not inhibit the drug-induced convulsions in control DDY mice. When administered intravenously (i.v.) to DDY mice, nefiracetam and other piracetam-like nootropics inhibited the Ro 5-4864-induced convulsions in the sequence of nefiracetam>aniracetam>>oxiracetam, piracetam. Spontaneous EL mouse seizures were also inhibited by these nootropics with a similar rank order of potencies. Binding studies for PBRs, performed on crude membranes of brain tissues of these mice, revealed that [3H]Ro 5-4864 and [3H]PK 11195 bindings were both inhibited by micromolar concentrations of nootropic agents in the sequence of nefiracetam> aniracetam>>oxiracetam, piracetam. The results suggest that nefiracetam may exert an anticonvulsant action through interacting with a low-affinity type of PBR in the brain, and could be developed as a promising therapeutic drug for neurological disorders including epilepsies.

A 'long-term-potentiation-like' facilitation of hippocampal synaptic transmission induced by the nootropic nefiracetam

Nefiracetam, a nootropic agent, enhanced the slope of field excitatory postsynaptic potentials in the CA1 region of rat hippocampal slices to about 170% of basal levels, being evident still at 4-h washing-out of the drug. A similar sustained enhancement (>/=16 h after i.m. injection with nefiracetam) was observed in the population spikes recorded from the granular cell layer of the intact mouse hippocampus. Saturation of the enhancement in the synaptic strength occluded potentiation obtained with long-term potentiation (LTP) induced by high-frequency (tetanic) stimulation, and vice versa. Interestingly, the facilitatory action of nefiracetam was blocked by either the nicotinic acetylcholine (ACh) receptor antagonists, alpha-bungarotoxin and mecamylamine, or the selective protein kinase C (PKC) inhibitor, GF109203X, but in contrast, it was not affected by D-2-amino-5-phosphonovaleric acid (APV), a selective N-methyl-D-aspartate (NMDA) receptor antagonist. The results of the present study suggest that nefiracetam, whereas the action is independent of NMDA receptors, induces an 'LTP-like' facilitation of hippocampal synaptic transmission as a consequence of modulation of nicotinic ACh receptors and PKC. This may represent a likely mechanism underlying the cognition-enhancing actions of nefiracetam.

Nefiracetam prevents propofol-induced anterograde and retrograde amnesia in the rodent without compromising quality of anesthesia

BACKGROUND

Propofol is a short-acting intravenous anesthetic agent. However, cognitive function remains depressed for several hours thereafter. We have evaluated the ability of nefiracetam, a novel cognition-enhancing agent, to alleviate propofol-induced amnesia in a rodent model of learning.

METHODS

Rats were trained in a one-trial, step-through, light-dark passive avoidance paradigm. Propofol (10 and 75 mg/kg) was administered by the intraperitoneal route at 15 min before training and separately at increasing times in the immediate 0-6 h post-training period (100 and 150 mg/kg). Nefiracetam, 9 mg/kg, was administered by the intraperitoneal route 1 h before training. Animals were tested for recall at the 12 h post-training time, and after their killing, immunocytochemistry was used to determine the increase in hippocampal neuronal polysialylation, an event associated with memory consolidation. Induction and duration of anesthesia induced by propofol was determined using tail pinch and pedal withdrawal reflexes.

RESULTS

Propofol-induced anterograde amnesia occurred in a dose-dependent manner. Induction of retrograde amnesia required a higher dose of propofol, which anesthetized the animals and was effective only in the immediate 3-h post-training period. In the absence of any evident effect on the onset or duration of anesthesia, nefiracetam prevented both forms of propofol-induced amnesia and preserved the learning-associated changes of neuronal polysialylation state.

CONCLUSIONS

The ability of nefiracetam to prevent propofol-induced anterograde and retrograde amnesia is proposed to be indirect and to result from modulation of gene transcription in a manner that initiates a cascade of events involving protein synthesis leading to synaptic growth associated with the formation of the long-term memory trace.

[Mitochondrial benzodiazepine receptors (MBR) in association with neurological disorders]

Ro 5-4864, a specific agonist of the peripheral-type benzodiazepine receptor (PBR), elicited convulsions 2.6 times more potently in EL mice (an animal model of epilepsy) than in DDY mice (control animal). A binding assay revealed a 50% higher density of [3H] Ro 5-4864 binding sites in the mitochondrial fraction (i.e., mitochondrial benzodiazepine receptors; MBR) of the brain tissues in EL mice as compared with DDY mice. On an elevated plus-maze, EL mice showed fear responses similar to those increased in DDY mice after PBR stimulation, suggesting a hyperfunction of MBR underlying the abnormal behaviors of EL mice. In fluorometric studies using NG108-15 cells, Ro 5-4864 depolarized mitochondrial membranes and, possibly as a consequence of this, raised intracellular Ca2+. Finally, we propose that MBR could be a major target of therapy for various neurological disorders, so drugs such as "mitochondrial membrane stabilizers" should be developed.

Nefiracetam modulates acetylcholine receptor currents via two different signal transduction pathways

Nootropic agents are proposed to serve as cognition enhancers. The underlying mechanism, however, is largely unknown. The present study was conducted to assess the intracellular signal transduction pathways mediated by the nootropic nefiracetam in the native and mutant Torpedo californica nicotinic acetylcholine (ACh) receptors expressed in Xenopus laevis oocytes. Nefiracetam induced a short-term depression of ACh-evoked currents at submicromolar concentrations (0.01-0.1 microM) and a long-term enhancement of the currents at micromolar concentrations (1-10 microM). The depression was caused by activation of pertussis toxin-sensitive, G protein-regulated, cAMP-dependent protein kinase (PKA) with subsequent phosphorylation of the ACh receptors; in contrast, the enhancement was caused by activation of Ca(2+)-dependent protein kinase C (PKC) and the ensuing PKC phosphorylation of the receptors. Therefore, nefiracetam interacts with PKA and PKC pathways, which may explain a cellular mechanism for the action of cognition-enhancing agents.

Cellular mechanisms underlying cognition-enhancing actions of nefiracetam (DM-9384)

We have studied cellular mechanisms underlying cognition-enhancing actions of nefiracetam (DM-9384), a newly developed cognitive enhancer, by biochemical experiments on cholinergic and GABAergic transmissions as well as electrophysiological experiments on neuronal Ca2+ channels. In behavioral experiments in rats, nefiracetam (3 mg/kg) ameliorated amnesia induced by basal forebrain (BF) lesion or treatment of scopolamine. Biochemical experiments revealed that nefiracetam increased uptake and release of transmitters in both cholinergic and GABAergic systems in rat brain. In electrophysiological studies, nefiracetam (1 microM) increased long-lasting (N/L-type) Ca2+ channel currents in NG108-15 cells. The nefiracetam action on Ca2+ channels was blocked by pertussis toxin (PTX). The results suggest that nefiracetam improves impaired memory by facilitating cholinergic and GABAergic transmissions in the brain. It is further suggested that PTX-sensitive G-proteins and Ca2+ channels associated with these G-proteins are responsible for the action of nefiracetam on neurotransmission.

Effects of nefiracetam on amnesia animal models with neuronal dysfunctions

The effects of N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide (nefiracetam; DM-9384), on learning and memory in several amnesia animal models with neuronal dysfunctions were investigated. Nefiracetam improved scopolamine-, bicuculline-, picrotoxin-, ethanol-, chlordiazepoxide- and cycloheximide-induced amnesia. Anti-amnesic action of nefiracetam on scopolamine model was antagonized by nifedipine and flunarizine, but not by diltiazem. Repeated administration of nefiracetam to AF64A-treated animals improved impairment of learning and memory as well as the alterations in cholinergic and monoaminergic neurotransmitters in the hippocampus. Basal forebrain (BF) lesioned rats induced by excitotoxin or by thermal coagulation showed impairment of learning accompanied by a marked reduction in choline acetyltransferase (ChAT) and acetylcholine esterase activities. Nefiracetam improved the learning deficit of the BF-lesioned rats. Nefiracetam also improved the carbon monoxide-induced delayed and acute amnesia. Nefiracetam stimulated acetylcholine release in the frontal cortex. Repeated administration of nefiracetam increased ChAT activity, gamma-aminobutyric acid (GABA) turnover and glutamic acid decarboxylase activity, and facilitated the Na(+)-dependent high-affinity GABA uptake. Nefiracetam activated the high voltage-activated (N/L-type) Ca2+ channel. The dose-response curves of nefiracetam were bell-shaped in both behavioral and biochemical studies. Therefore, it is suggested that nefiracetam improves the dysfunction of cholinergic, GABAergic and/or monoaminergic neuronal function by acting at Ca2+ channel and enhancing the release of neurotransmitters, and modifies impairment of memory processes induced by drugs and hypoxia.

Influence of nefiracetam on NGF-induced neuritogenesis and neural cell adhesion molecule polysialic acid expression: in vivo and in vitro comparisons

Previously, the ability of co-administered nefiracetam to reverse scopolamine-induced learning deficits has been attributed to the preservation of a transient increase in neural cell adhesion molecule (NCAM) polysialylation state during a late phase of memory consolidation (Doyle et al., J. Neurosci. Res., 31 (1992) 513-523). Using the PC-12 pheochromocytoma cell model, we now demonstrate nefiracetam pre-exposure to significantly enhance nerve growth factor-induced neuritogenesis and NCAM polysialylation, but not prevalence, in a dose-dependent manner with maximal effects being observed at the lowest dose (0.1 microM) examined. As the memory-associated increase in NCAM polysialylation in vivo is associated with a defined group of neurons at the dentate hilar/granule cell layer border (Regan and Fox, Neurochem. Res., 20 (1995) 521-526), the effect of chronic nefiracetam exposure in vivo was evaluated. Once-daily, intraperitoneal administration of either 3 or 9 mg/kg nefiracetam to adult male Wistar rats for 40 days significantly increased the number of hippocampal dentate polysialylated neurons only at the highest dose evaluated, suggesting it to prevent their age-dependent decline. These results are consistent with nefiracetam facilitating early induction events of long-term memory consolidation processes involving NCAM polysialylation state.

Cancer-associated retinopathy syndrome: a case of small cell lung cancer expressing recoverin immunoreactivity

Cancer-associated retinopathy (CAR) syndrome is a rare paraneoplastic neuropathy syndrome often found in patients with small cell lung cancer (SCLC). Serological studies have indicated that the process could include autoimmune reactions directing retinal antigens. Recently, the CAR antigen was identified as a photoreceptor protein, recoverin, by screening retinal proteins using the CAR patient's serum. The present case of SCLC showed rapidly deteriorated bilateral visual acuity lacking the inflammatory findings at the retina which were compatible with CAR. The immunohistochemical study revealed that the cancer cells expressed recoverin or recoverin-like immunoreactivity. This is the first observation in CAR syndrome. The presence of recoverin or recoverin-like immunoreactivity in SCLC with CAR syndrome supports the hypothesis that the cancer-retina immunologic cross-reaction contributes to visual loss in this syndrome.

Nefiracetam (DM-9384) reverses apomorphine-induced amnesia of a passive avoidance response: delayed emergence of the memory retention effects

Nefiracetam is a novel pyrrolidone derivative which attenuates scopolamine-induced learning and post-training consolidation deficits. Given that apomorphine inhibits passive avoidance retention when given during training or in a defined 10-12h post-training period, we evaluated the ability of nefiracetam to attenuate amnesia induced by dopaminergic agonism. A step-down passive avoidance paradigm was employed and nefiracetam (3 mg/kg) and apomorphine (0.5 mg/kg) were given alone or in combination during training and at the 10-12h post-training period of consolidation. Co-administration of nefiracetam and apomorphine during training or 10h thereafter produced no significant anti-amnesic effect. However, administration of nefiracetam during training completely reversed the amnesia induced by apomorphine at the 10h post-training time and the converse was also true. These effects were not mediated by a dopaminergic mechanism as nefiracetam, at millimolar concentrations, failed to displace either [3H]SCH 23390 or [3H]spiperone binding from D1 or D2 dopamine receptor subtypes, respectively. It is suggested that nefiracetam augments molecular processes in the early stages of events which ultimately lead to consolidation of memory.

Peripheral-type benzodiazepine receptors in association with epileptic seizures in EL mice

Peripheral-type benzodiazepine receptors (PBR) in the brain were studied in association with epileptic seizures using EL mice, an animal model of epilepsy, and DDY mice as controls. Ro 5-4864 (i.p.), a specific agonist for PBR, elicited tonic-clonic convulsions in EL mice 2.6-times more potently than in DDY mice with CD50s of 11.9 and 31.2 mg/kg for EL and DDY mice, respectively. In contrast, pentylenetetrazole (i.p.) exerted convulsant actions on EL and DDY mice in a less differential way with CD50s of 29.2 and 48.1 mg/kg for EL and DDY mice, respectively. PK 11195 (i.v.), a specific antagonist for PBR, raised seizure thresholds of EL mice at a dose of 2 mg/kg. Binding assay revealed a 50% higher density of [3H]Ro 5-4864 binding sites in the mitochondrial fraction isolated from the cerebrum of EL mice in comparison with DDY mice. Similarly, a 40% higher density of [3H]flunitrazepam binding was observed in the mitochondrial fraction of EL mice. The results support the hypothesis that PBR, particularly those associated with mitochondria, are involved in the pathogenesis of epileptic seizures in EL mice.

Organic solvent-tolerant bacterium which secretes an organic solvent-stable proteolytic enzyme

A bacterial strain which can be grown in a medium containing organic solvents and can secrete a proteolytic enzyme was isolated and identified as Pseudomonas aeruginosa. The strain was derived by the following two-step procedures: high proteolytic enzyme producers were first isolated by the usual method, and then the organic solvent-tolerant microorganism was selected from these high-rate proteolytic enzyme producers. The proteolytic activity of the supernatant of the culture was stable in the presence of various organic solvents. The stability of the enzyme in the presence of organic solvents, of which the values of the logarithm of the partition coefficient (log P) were equal to or more than 3.2, was almost the same as that in the absence of organic solvents. It is expected that both the solvent-tolerant microorganism and the solvent-stable enzyme produced by this strain can be used as catalysts for reactions in the presence of organic solvents.

Fetal loss in the first trimester after demonstration of cardiac activity: relation of cytogenetic and ultrasound findings

A retrospective comparison of cytogenetic and ultrasound findings in first trimester spontaneous fetal loss after demonstration of cardiac activity was made. The crown-rump length (CRL) was measured twice for each fetus resulting in spontaneous abortion: (i) CRL was measured in the viable state while demonstrating cardiac activity, and the growth deviation was expressed as the measured/expected CRL ratio (M/E CRL ratio); (ii) in the same fetus, CRL was measured after confirmation of fetal death, and designated as the post-mortem CRL. The chorionic tissues of these abortuses were karyotyped. The CRL of fetuses which resulted in normal deliveries were also measured as controls. As a result, 16 of 24 abortuses displayed an abnormal chromosomal analysis (67%). The mean M/E CRL ratio of still-viable fetuses was smaller than that of control fetuses (0.74 +/- 0.20 versus 0.98 +/- 0.13 respectively, P < 0.01). The differences in ratio between karyotypically normal and abnormal abortuses were not statistically significant. The post-mortem CRL of dead fetuses was > 20 mm in four of five monosomy X, two of three 21-trisomy, one of three triploidy and none of eight embryos with normal karyotype and five other trisomies. In conclusion, our study demonstrated that the M/E CRL ratio could be used as a predictor of spontaneous abortions, although it does not discriminate abnormal karyotypes from normal ones. The embryos with a post-mortem CRL more than 20 mm have a higher likelihood of suffering monosomy X or 21-trisomy. The ultrasonographic findings might offer a cytogenetic clue as to a possible cause to the developmental arrest.

[Maternal serum alpha-fetoprotein as a screening test for fetal Down syndrome]

An association between a low maternal serum alpha-fetoprotein (MSAFP) level and an increased incidence of Down syndrome is well documented. This study was undertaken to elucidate the diagnostic efficacy of MSAFP as a screening test for Down syndrome in 711 Japanese women who underwent genetic amniocentesis between 14 and 20 gestational weeks of age in Hyogo Medical College Hospital. The mean value for the multiple of the median (MoM) of the MSAFP level in 11 pregnancies associated with Down syndrome was 0.78 +/- 0.47 and 1.12 +/- 0.67, respectively. A cut-off value of < 0.45, < 0.50, < 0.55 and < 0.60 MoM yielded negative predictive values of 98.6%, 98.5%, 99.0% and 99.2%, positive predictive values of 6.3%, 4.0%, 9.1% and 8.6%, a sensitivity of 9.1%, 9.1%, 36.4% and 54.5%, and false positive rates of 2.1%, 3.4%, 5.7% and 9.1%, respectively. The combining of MSAFP and maternal age improves the expected results of a strategy for Down syndrome.

Effects of nefiracetam on deficits in active avoidance response and hippocampal cholinergic and monoaminergic dysfunctions induced by AF64A in mice

The effects of nefiracetam [DM-9384; N-(2,6-dimethyl-phenyl)-2-(2-oxo-pyrrolidinyl)acetamide] and of phosphatidylcholine on a step-up active avoidance response, locomotor activities and regional brain cholinergic and monoaminergic neurotransmitters in AF64A-treated mice were investigated. Intracerebroventricular (i.c.v.) injection of AF64A (ethylcholine mustard aziridinium ion; 8 nmol/ventricle) impaired acquisition and retention of the avoidance task, and increased vertical and horizontal locomotor activities. Regional levels of acetylcholine, noradrenaline, 3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were significantly decreased and homovanillic acid (HVA) levels were increased in the hippocampus but not in the septum, cerebral cortex or striatum of AF64A-treated animals. Administration of nefiracetam (3 mg/kg, p.o.) twice daily for 9 days to AF64A-treated animals ameliorated the deficit in active avoidance response in addition to attenuating the increase in locomotor activities. In parallel with these behavioural effects, nefiracetam reversed AF64A-induced alterations in the hippocampal profiles of cholinergic and monoaminergic neurotransmitters and their metabolites. In contrast, administration of phosphatidylcholine (30 mg/kg, p.o.) twice daily for 9 days had no significant effect on the deficit in active avoidance response, despite significantly reversing the decrease in acetylcholine levels in the hippocampus. These results indicate that the effects of nefiracetam on AF64A-induced behavioural deficits are probably due to its ability to facilitate both cholinergic and monoaminergic neurotransmitter systems.

Effects of nefiracetam (DM-9384), a pyrrolidone derivative, on brain monoamine systems

The pyrrolidone cyclic gamma-aminobutyric acid (GABA) derivative nefiracetam [DM-9384; N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide] has been shown to enhance acquisition and ameliorate amnesia in different learning tasks in rodents. In the present study, the effects of nefiracetam on the brain monoamine systems were studied. Male, adult Sprague-Dawley rats were treated with nefiracetam in single doses (0, 1, 3, 10, 30 or 100 mg/kg, p.o.) and analyzed after 1 and 4 hr, or treated by daily doses (0, 1, 3, 10 or 30 mg/kg, p.o.) for 2 weeks. In general, no or only weak effects were observed on tissue monoamine levels, either following acute or 14 days treatment with nefiracetam. Acute administration of intermediate doses of nefiracetam induced minor increases in dopamine (DA) and homovanillic acid (HVA) tissue levels in the striatum, while hypothalamic 3,4-dihydroxyphenylacetic acid (DOPAC) decreased at 1 hr. Noradrenaline (NA) and serotonin (5-HT) levels increased in some regions after higher doses of nefiracetam. Increases in 5-hydroxyindoleacetic acid (5-HIAA) were also seen at 4 hr, but only after the 3 mg/kg dose. Minor decreases of HVA and DOPAC levels were seen in some regions after treatment with various doses of nefiracetam for 14 days, while an increase in 5-HT levels was observed occasionally. Using in vivo microdialysis in freely moving animals, no significant effects on extracellular levels of HVA, DOPAC and 5-HIAA in the striatum or of HVA, DOPAC and NA levels in the dorsal hippocampus were seen after acute administration of nefiracetam. On the other hand, extracellular hippocampal 5-HIAA levels decreased by 20% after the 1 and 3 mg/kg doses. Nefiracetam, in a concentration range of 1 nM to 10 microM, did not affect the in vitro synaptosomal uptake of [3H]NA and [3H]5-HT in the cortex or of [3H]DA in the striatum. Taken together, nefiracetam appears to exert minor, regionally restricted and not dose-dependent effects on the monoamine systems following either acute or repeated administrations in normal rats. A direct or indirect, possible GABA-mediated, influence of nefiracetam may underlie the modest changes seen on monoamines. The cognitive-enhancing action of nefiracetam does not seem to be related to effects on presynaptic monoamine functions.

Possible involvement of the activation of voltage-sensitive calcium channels in the ameliorating effects of nefiracetam on scopolamine-induced impairment of performance in a passive avoidance task

We investigated the effects of various types of calcium channel antagonists on the amelioration by nefiracetam [N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide, DM-9384] of scopolamine-induced impairment of performance in a passive avoidance task in mice. The reversal of the scopolamine-induced impairment of performance by nefiracetam showed a bell-shaped plot. Both i.p. and i.c.v. injection of L-type calcium channel antagonists such as nifedipine and flunarizine attenuated the ameliorating effects of nefiracetam, although diltiazem had no effect. Neomycin, an N-type calcium channel antagonist, also attenuated these effects of nefiracetam in a dose-dependent manner. Further, LaCl3 but not NiCl2 showed inhibitory effects on the amelioration by nefiracetam. These results suggest that the activation of high-voltage-activated, but not low-voltage-activated, calcium channels is involved in the ameliorating effects of nefiracetam on scopolamine-induced impairment of performance in a passive avoidance task.

Inhibitory activity of chlorophyllin on the genotoxicity of carcinogens in Drosophila

Antimutagenic activity of copper chlorophyllin against various carcinogenic mutagens was assayed with Drosophila genotoxicity tests, i.e., the wing spot test for detecting somatic cell mutations and the DNA repair test for detecting DNA damage. In these tests, Drosophila larvae were fed carcinogens together with chlorophyllin. Polycyclic aromatic compounds, including heterocyclic amines, polycyclic aromatic hydrocarbons, aromatic amines and aromatic nitro compounds, were subject to inhibition, with a few exceptions. The results support the view that chlorophyllin traps carcinogens by forming complexes, thereby inhibiting the absorption of these compounds from the digestive tract. Consistent with this mechanism, Sepharose-supported chlorophyllin in the feed inhibited the Trp-P-2-induced wing spot formation, while Sepharose itself was ineffective.

Effects of nefiracetam on drug-induced impairment of latent learning in mice in a water finding task

We investigated the effects of nefiracetam (DM-9384), a pyrrolidone derivative, on chlordiazepoxide-, apomorphine-, and methamphetamine-induced impairment of latent learning in a water finding test in mice. Pretreatment with nefiracetam reversed the inhibitory effects of chlordiazepoxide and apomorphine, but not those of methamphetamine, on latent learning. The ameliorative effects of nefiracetam on apomorphine-induced, but not chlordiazepoxide-induced impairment of latent learning were antagonized by scopolamine. These results provide further evidence that nefiracetam has anti-amnesic effects. Further, it is suggested that the cholinergic neuronal system may be involved in the ameliorative effects exerted by nefiracetam on apomorphine-induced impairment of latent learning.

[Laparoscopic resection of ovarian cysts: precautions and improvements in the procedure and application of the mini-laparotomy]

We previously devised and reported a laparoscopic resection of benign ovarian cysts. In the present paper, we report precautions and improvements in the procedure and the application of the mini-laparotomy. 1. The subjects consisted of a total of 41 cases with preoperatively diagnosed cysts. These were 17 cases with simple cysts, 15 cases with dermoid cysts, and nine cases with chocolate cysts. The present surgical procedure was performed on 34 (83%) cases. 2. One case, preoperatively diagnosed as a chocolate cyst, was diagnosed as an endometrioid adenocarcinoma. 3. Laparotomy was required in 7 cases; in four as a result of hard adhesions, in one because it was impossible to withdraw fluid, in one due to a damaged urinary bladder and in one due to endometrioid adenocarcinoma. 4. It became essential to classify the ovarian cysts into three groups according to size. 5. Mini-laparotomy was performed for two giant ovarian cysts and five ovarian cysts in pregnant women. In this procedure the goal is minimal, simple, safe and reliable surgery with results equal to those of standard laparotomy.

Nefiracetam (DM-9384) preserves hippocampal neural cell adhesion molecule-mediated memory consolidation processes during scopolamine disruption of passive avoidance training in the rat

Scopolamine (0.15 mg/kg), a muscarinic antagonist, when administered during training or at a discrete 6-h posttraining time point, is demonstrated to inhibit the recall of a step-down passive avoidance response when tested at 24 and 48 h after task acquisition. Nefiracetam (3 mg/kg), a piracetam-related nootropic, when given with scopolamine during training tended to improve task recall, and this effect was more pronounced when given at the 6-h posttraining time. Co-administration of nefiracetam with scopolamine was not necessary to achieve the antiamnesic action, as nefiracetam given during training significantly improved the memory deficits produced by scopolamine at the 6-h posttraining time. The paradigm-specific increase in hippocampal neural cell adhesion molecule sialylation, which is observed during consolidation of a passive avoidance response, was attenuated by the presence of scopolamine during training and at the 6-h posttraining time, and this effect was reversed by co-administration of nefiracetam, albeit in a paradigm-independent manner. These results suggest nefiracetam exerts a neurotrophic action that protects memory consolidation from drug interventive insults.

[Laparoscopy-guided extraperitoneal resection of ovarian cysts: surgical procedure, indications and limitations]

We designed a new surgical method for the treatment of benign ovarian cysts. We have previously reported that, with our laparoscopy-guided method, the cyst wall is pulled outside the abdominal cavity after evacuation of the cyst contents, and resection is performed by the same method as during laparotomy. The preoperative assessment and surgical findings were investigated in 16 subjects, 5 with simple cysts, 2 with para-ovarian cysts, 2 with chocolate cysts, 5 with dermoid cysts and 2 with mucinous cysts. This surgical method was applicable in 11 of the 14 patients. Laparotomy was required in the other 3, because 2 of the patients had strong adhesions and in 1 evacuation was impossible. The patients were classified into 3 grades of difficulty before surgery: Grade I; operable, Grade II; operable with special care, Grade III; laparotomy required. During surgery, the feasibility of continuing the procedure was also assessed. In this surgical procedure, through a small incision in the abdominal wall, the entire resection of an ovarian cyst is done extra-peritoneally. However, the eligibility of patients for this method needs to be very carefully examined preoperatively and reviewed throughout the procedure.

Direct assay method for guanosine 5'-monophosphate reductase activity

A sensitive and simple micromethod for the accurate measurement of GMP reductase (EC 1.6.6.8) activity in crude extracts is described. The reaction product of [8-14C]IMP was separated from the substrate [8-14C]GMP by descending chromatography on Whatman DE81 ion-exchange paper. This separation method provides an analysis of the possible interfering reactions, such as the metabolic conversion of the substrate GMP to GDP, GTP, and/or guanosine, and guanine and the loss of the product IMP to inosine, hypoxanthine, and other metabolites. Low blank values (70-90 cpm) were obtained consistently with this assay because the IMP spot moves faster than the GMP spot. The major advantages of this method are direct measurement of GMP reductase activity in crude extracts, high sensitivity (with a limit of detection of < 10 pmol of IMP production), high reproducibility (< +/- 5%), and capability to measure activity in small samples (9 micrograms protein).

[Nosocomial respiratory infection caused by Pseudomonas cepacia in immunocompromised hosts]

Pseudomonas cepacia is a gram negative rod, having no fermentative activity on glucose. This organism was detected in the sputum, throat swab, or throat washing of 22 inpatients treated between January, 1990, and December, 1990, at the First Department of Internal Medicine, Kagawa Medical School. The primary diseases for which these 22 patients were hospitalized were leukemia in 12, malignant lymphoma in 5, lung cancer in 2, myelodysplastic syndrome in 1, and embryonal cell carcinoma in 1. Twelve of the 22 patients had episodes of pneumonia which complied clinically with the diagnostic criteria provided to facilitate the National Nosocomial Infection Study. The complication of pneumonia occurred in 7 patients with leukemia, 2 with malignant lymphoma, 2 with lung cancer, and 1 with myelodysplastic syndrome. In 10 of these 12 patients, the organism was detected before the onset of pneumonia. All 22 patients in whom the organism was demonstrated had received antibiotics. The antibiotics which was most frequently used to treat these patients 1 month before detection of Pseudomonas cepacia were amikacin and ceftizoxime, which were used in 13 patients. Of the antibiotics in which the susceptibility to Pseudomonas cepacia was, evaluated, minocycline was effective in 100% (21/21), ceftazidime in 50% (11/22), and ofloxacin in 27.3% (6/22). Physicians should be especially aware of the possibility of colonization and nosocomial respiratory infection by Pseudomonas cepacia in patients with severe underlying diseases.

Elevation of plasma truncated elastase alpha 1-proteinase inhibitor complexes in patients with inflammatory lung diseases

Human neutrophil elastase plays an important role in the development of several inflammatory lung diseases; however, there have been relatively few investigations using plasma samples. In this report, we describe alterations in the plasma elastase:alpha 1-PI complex in patients with chronic obstructive pulmonary disease (COPD) (15 cases), COPD with infection (8), diffuse panbronchiolitis (DPB) (8), bronchiectasis (9), pneumonia (10), and the adult respiratory distress syndrome (ARDS) (14), and in 15 normal volunteers. The elastase:alpha 1-PI complex concentration was determined by an enzyme-linked immunosorbent assay. Western immunoblot analysis of the elastase:alpha 1-PI complex was also performed. Plasma elastase:alpha 1-PI complex was also performed. Plasma elastase:alpha 1-PI complex levels in patients with COPD with infection (504 micrograms/L +/- 93 micrograms/L) were significantly higher, as compared with those with COPD but without infection (118 micrograms/L +/- 9 micrograms/L) and normal volunteers (122 micrograms/L +/- 4 micrograms/L). Increased complex concentrations were also found in patients with DPB and bronchiectasis (643 micrograms/L +/- 222 micrograms/L and 558 micrograms/L +/- 198 micrograms/L, respectively) as compared with normal volunteers. Increased complex concentrations were also found in patients with pneumonia and ARDS (450 micrograms/L +/- 101 micrograms/L and 1,400 micrograms/L +/- 438 micrograms/L, respectively). Western immunoblot analysis using anti-alpha 1-PI antibody and antineutrophil elastase antibody showed two types of elastase:alpha 1-PI complexes, one with a molecular weight of 60,000 daltons (60 kilodaltons [KD]) and the other at 50,000 daltons (50 KD). Although the native 80-KD elastase:alpha 1-PI complex was detected in bronchoalveolar lavage fluid, it was not found in plasma. In summary, these results demonstrated that levels of the truncated complex were increased in patients with various inflammatory lung diseases. This truncated form may play an important role in the pathophysiology of inflammatory processes.

Involvement of the cholinergic system in the effects of nefiracetam (DM-9384) on carbon monoxide (CO)-induced acute and delayed amnesia

The effects of N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)-acetamide (DM-9384, nefiracetam), a cyclic derivative of GABA, were investigated in the carbon monoxide (CO)-induced amnesia model in mice using the passive avoidance task. Memory deficiency occurred when mice were exposed to CO before memory was completely consolidated after training (acute amnesia), at 7 days before training and 7 days after training (delayed amnesia). DM-9384 prolonged the step-down latency in mice with CO-induced amnesia. Scopolamine blocked the anti-amnesic effect of DM-9384 on delayed amnesia that had been induced by pre- or post-training exposure to CO. Bicuculline had a tendency to antagonize the anti-amnesic effect of DM-9384, but this tendency was not significant. Under these conditions, no significant change in the activity of choline acetyltransferase and glutamic acid decarboxylase was observed in the frontal cortex, striatum and hippocampus. These results suggest that DM-9384 potentiates cholinergic neuronal function and that it may modify acquisition and/or consolidation of memory.

Effects of nefiracetam, DM-9384 on amnesia and decrease in choline acetyltransferase activity induced by cycloheximide

The effects of nefiracetam, [N-(2,6-dimethyl-phenyl)-2-(2-oxo-pyrrolidinyl)acetamide, DM-9384], a cyclic derivative of GABA, were investigated in the cycloheximide (CXM)-induced amnesia animal model using the passive avoidance task. Pre-training administration of DM-9384 attenuated the CXM-induced amnesia as indicated by prolongation of step-down latency. It protected against CXM-induced inhibition of choline acetyltransferase activity in the cerebral cortex. These results suggest that DM-9384 attenuates CXM-induced amnesia by interacting with AChergic neuronal system and enhancing protein synthesis in the brain.

[Pilot phase II trial of high-dose etoposide combined with cisplatin in the treatment of refractory lung cancer]

The efficacy of combined high-dose etoposide with standard dose cisplatin was evaluated in patients who had refractory lung cancer after standard chemotherapy. Each patient was given etoposide at 500 mg/m2/day on day 1 to 3 continuously (total dose 1,500 mg/m2) and cisplatin at 80 mg/m2 on day 1. Fifteen patients (7 adenocarcinoma, 5 small cell lung cancer, 2 squamous cell lung cancer and 1 sarcoma, which latter was difficult to distinguish from giant cell carcinoma) were entered in this study. The overall response was 41.7% (5 of 12); five partial response, 6 no change, and 1 progressive disease. Three treatment-related deaths were observed; one resulted from sepsis and two from respiratory failure because of tumor progression. All of the patients developed severe myelosuppression; the mean nadir white blood cell count was 400, and the mean nadir platelet count was 24,000 in 28 evaluable courses. The range of maximum concentration of etoposide determined by HPLC was from 17.4 to 39.1 micrograms/ml. These results suggest that high-dose etoposide combined with a standard dose of cisplatin is effective against refractory lung cancer.

E. coli gpt gene expression effects on K562 human leukemia cell proliferation and erythroid differentiation altered by mycophenolic acid

Inosine monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) inhibitors including mycophenolic acid (MPA) were reported to induce K562 human leukemia cells to differentiate into erythroid cells. A shuttle vector plasmid pMSG containing E. coli xanthine-guanine phosphoribosyl transferase (Eco gpt) gene was transfected into K562 cells (K562-pMSG cells) to investigate the role of IMPDH in both K562 cell proliferation and erythroid differentiation. Eco gpt provides K562 cells with an additional salvage pathway for GMP production from xanthine. In the presence of xanthine, K562-pMSG cells continued to proliferate and did not differentiate to erythroid cells regardless of the presence of MPA, but they discontinued proliferating and differentiated into the erythroid lineage in the absence of xanthine. Proliferation and differentiation of control K562 cells into erythroid cells were suppressed by MPA regardless of the presence or absence of xanthine. Addition of guanosine maintained the proliferation and blocked the erythroid differentiation of K562 and K562-pMSG cells induced by MPA even in the absence of xanthine. These data indicate that a decrease in the activity of IMPDH and a subsequent decline in the concentration of guanine nucleotides caused by MPA resulted in the induction of the erythroid differentiation and discontinuation of the proliferation of K562 cells.

Effects of DM-9384, a pyrrolidone derivative, on ischemia-induced changes in the central monoamine systems

Alterations in brain tissue levels of monoamines and monoamine metabolites were studied in gerbils 60 min after cerebral ischemia induced by 10 min carotid ligation after pretreatment with the antiischemic drug DM-9384 (1, 3, 10, 30 mg/kg, PO). The DA levels decreased in striatum after the ischemia, while cortical and hippocampal DA levels increased. The DOPAC levels increased in cortex, but were essentially unaffected in other regions. The HVA levels increased in all forebrain regions studied. NA levels decreased in hippocampus and superior colliculus, while a general increase in MHPG levels was seen. Decreases in 5-HT levels were seen in all forebrain regions except cortex. The 10 mg/kg and 30 mg/kg doses of DM-9384 counteracted the decrease in striatal 5-HT and hypothalamic MHPG/NA ratio, respectively. Thus pretreatment with DM-9384 exerted minor protective effects on the alterations induced in monoamine systems by transient forebrain ischemia.

Induction of erythroid differentiation of K562 cells by 4-carbamoylimidazolium 5-olate (SM-108)

The effects of 4-carbamoylimidazolium 5-olate (SM-108), an antipurine compound, on a human leukemia cell line, K562, were studied. Treatment with SM-108 induced erythroid differentiation of K562 cells. During a 6-day culture with 100 microM SM-108, the cell number decreased to 37% of the control number, 77% of the cells became benzidine-positive, and the hemoglobin content increased from 2.1 +/- 0.2 to 10.6 +/- 1.3 pg/cell. Cell differentiation was associated with reduction of IMP dehydrogenase activity and intracellular GTP content to 25 and 36%, respectively, of the control values within 1.5 hr. The differentiation and decrease in the GTP pool induced by SM-108 were blocked by the presence of 25 microM guanine or guanosine. SM-108 also induced erythroid differentiation of K562 subline cells transfected with pMSG (K562/pMSG), which have an additional salvage pathway for GMP production from xanthine. The addition of 100 microM xanthine prevented erythroid differentiation of this subline and restored the GTP pool. These findings suggest that the induction of erythroid differentiation of K562 cells by SM-108 may be due to an early decrease in IMP dehydrogenase activity and a subsequent decrease in GTP content in the cells. Thus, purine metabolism may have an important role in SM-108-induced differentiation.