Medial septal injection of naloxone elevates acetylcholine release in the hippocampus and induces behavioral seizures in rats

The effects of injections of naloxone, a universal opioid receptor antagonist, into the medial septal nucleus on hippocampal acetylcholine (ACh) release and behavior were investigated in freely moving rats by means of the microdialysis method. The injection of naloxone (2, 10 and 20 micrograms) produced a marked increase in hippocampal ACh release in a dose-dependent manner. These effects of naloxone were reversed by the post-injection of [D-Ala2, N-Me-Phe4, Gly-ol]-enkephalin (DAGO; 10 micrograms), an opioid mu receptor agonist. Furthermore, basal release of hippocampal ACh was significantly reduced by the injection of DAGO alone. It was also found that rats given an injection of naloxone showed an increase in motor activity and occasionally exhibited behavioral seizures. These effects of naloxone were also reversed by the post-injection of DAGO. The present results suggest that endogenous opioids ionically inhibit the activity of septo-hippocampal cholinergic neurons via mediation of mu opioid receptors in the medial septal nucleus. They also suggest that endogenous opioids modulate the incidence of seizures, at least in part, through opioid mu receptors in the medial septal nucleus.

Non-traumatic arteriovenous fistulas of the scalp treated by a combination of embolization and surgical removal

Three patients with non-traumatic arteriovenous fistulas (AVFs) of the scalp were treated by embolization using acrylate glue through the transarterial route or by direct puncture of the lesions and then surgical resection. Complete cure was achieved in all three patients. Selective angiography is indispensable in the correct diagnosis of scalp AVFs. Embolization facilitates surgical removal when necessary, and this combination is the treatment of choice for scalp AVFs.

Age-related changes in the metabolism of neurotransmitters in rat striatum: a microdialysis study

Rats from one month to 22 months of age were subjected to in vivo brain microdialysis under a free-moving condition. The 3,4-dihydroxyphenylacetic acid level in the striatum reached a maximum at 3 months old. However, both basal and potassium-induced dopamine release were maximal at 1.5 months, which represents sexual maturation (puberty). The inhibitory effect of monoamine oxidase (MAO) activity by pargyline was maximal at 1.5 months. The delayed maximum level of the metabolites may be due to different age-related changes in MAO-A and MAO-B. From these results, it is suggested that in the rat striatum, the release of dopamine is maximal at the age of sexual maturation, and that the whole synaptic function of the dopaminergic neurons is at its highest during late adolescence.

Endothelin-1 is involved in mechanical stress-induced cardiomyocyte hypertrophy

We have recently shown that mechanical stress induces cardiomyocyte hypertrophy partly through the enhanced secretion of angiotensin II (ATII). Endothelin-1 (ET-1) has been reported to be a potent growth factor for a variety of cells, including cardiomyocytes. In this study, we examined the role of ET-1 in mechanical stress-induced cardiac hypertrophy by using cultured cardiomyocytes of neonatal rats. ET-1 (10(-8) approximately 10(-7) M) maximally induced the activation of both Raf-1 kinase and mitogen-activated protein (MAP) kinases at 4 and 8 min, respectively, followed by an increase in protein synthesis at 24 h. All of these hypertrophic responses were completely blocked by pretreatment with BQ123, an antagonist selective for the ET-1 type A receptor subtype, but not by BQ788, an ET-1 type B receptor-specific antagonist. BQ123 also suppressed stretch-induced activation of MAP kinases and an increase in phenylalanine uptake by approximately 60 and 50%, respectively, but BQ788 did not. ET-1 was constitutively secreted from cultured cardiomyocytes, and a significant increase in ET-1 concentration was observed in the culture medium of cardiomyocytes after stretching for 10 min. After 24 h, an approximately 3-fold increase in ET-1 concentration was observed in the conditioned medium of stretched cardiomyocytes compared with that of unstretched cardiomyocytes. ET-1 mRNA levels were also increased at 30 min after stretching. Moreover, ET-1 and ATII synergistically activated Raf-1 kinase and MAP kinases in cultured cardiomyocytes. In conclusion, mechanical stretching stimulates secretion and production of ET-1 in cultured cardiomyocytes, and vasoconstrictive peptides such as ATII and ET-1 may play an important role in mechanical stress-induced cardiac hypertrophy.

A cyanobacterial gene that interferes with the phosphotransfer signal transduction involved in the osmoregulatory expression of ompC and ompF in Escherichia coli

Synechococcus sp. PCC7942 is a phototrophic cyanobacterium. In this study we cloned a Synechococcus gene that has a striking effect on the production of the Escherichia coli outer membrane proteins, OmpC and OmpF, provided that this gene was introduced by a multicopy plasmid into the heterologous cells. This multicopy gene in E. coli cells was able to specifically shut off the production of both OmpC and OmpF at the level of transcription. The nucleotides were sequenced for this gene, named sis, and its gene product was purified from E. coli to near homogeneity. A computer-aided search found that the deduced amino acid sequence consisting of 138 residues is novel, with no significant similarity to any other protein in the databases. Since the transcription of ompC and ompF is regulated by the regulatory factors EnvZ and OmpR, through phosphotransfer signal transduction, we explored the inhibitory effect of Sis in various genetic backgrounds as to envZ and ompR. In particular, the inhibitory effect of Sis was observed even in an DeltaenvZ background, but was not observed in a certain background in which the ompC and ompF transcription was supported by a mutant OmpR that can function in a phosphorylation-independent manner. These results suggested that the EnvZ kinase may not be the direct target of Sis, but rather that the process(es) concerning the phosphorylation and/or dephosphorylation of the OmpR protein may be affected by Sis. However, no direct effect of Sis was seen in an in vitro OmpR-phosphorylation assay with the purified OmpR and Sis proteins. Based on these results, possible functions of Sis are discussed with special reference to the phosphotransfer signal transduction in E. coli.

[Sociomedical study of centenarians in Nagoya City]

The purpose of this study was to assess the background to the longevity of 36 centenarians in Nagoya city and to compare 14 institutionalized centenarians out of those 36 with 202 individuals in the 70-99 age group in our special nursing home, particularly with regard to blood chemistry and immunity tests. The reasons for their social longevity in terms of profile appeared to be attention to eating habits, abstention from smoking and drinking, occupations with adequate exercise. The incidence of dementia was 65.6% among them. We evaluated centenarians from the viewpoint of Hasegawa's Dementia Scale (HDS) and comprehensive functional assessment of the elderly consisted of the revised version of Hasegawa's Dementia Scale (HDSR), and examination of activity of daily living (ADL), physical perception, and social life. All were positively associated. Thus centenarians independent of physical assistance demonstrated significantly higher systolic blood pressure, and respective scores for HDS, HDSR, ADL, physical perception and social life than their dependent counterparts, were less likely to be institutionalized and suffered from fewer disorders. In particular none were diagnosed as positive for cerebral hemorrhage, infarction and dementia. Age demonstrated significant positive or negative correlation with the following values in blood chemistry and immunity tests: blood cell counts, hemoglobin concentration, hematocrit value, albumin, total protein, total cholesterol, low density lipoprotein cholesterol, creatinine, blood cell nitrogen, uric acid, helper T cell, and IgA immunoglobulin.

[A clinical evaluation of chest wall reconstruction]

From April 1987 to June 1995, we performed the chest wall reconstruction in 13 cases of 25 ones who had chest wall resection. The clinical records of these 13 patients were reviewed as follows. The histological diagnosis of these cases were direct invasion by primary lung cancer in 13 cases, malignant tumor of the chest wall in 5 cases, benign tumor or inflammation of the chest wall in 4 cases, local recurrence of the breast cancer and post operative radiation ulcer in each 1 case respectively, and mediastinal peripheral nerve sheath tumor in 1 case. Full diagnosis of the mediastinal malignant tumors were Ewing' sarcoma, chondrosarcoma, malignant lymphoma, malignant fibrous histiocytoma and eosinophilic granuloma in each 1 case respectively. The total number of resected ribs was 10 (bilateral 5 ribs with sternal body) in 1 case, 4 in 1 case, 3 in 6 cases, 2 in 2 cases and 1 in 4 cases. The following statement shows our methods of chest wall reconstructions. We treated one case with wide anterior chest wall resection, we treated by the Marlex-resin sandwich, 4 cases with 4 or 3 ribs of anterior or lateral chest wall, by sheets of Marlex mesh in layers, 3 cases with 3 ribs of posterior site, 1 case with 2 ribs and 4 cases with one rib, these 7 cases treated by cross sutures. And, we treated another 2 cases by pedicle omental flap and major pectoral muscle in each case respectively. The Marlex-resin sandwich has easy fixation and excellent stability, but it has also foreign body reaction. Therefore our case needed to remove of sandwich 10 months later for cellulitis and infection after the operation. Recently we use mostly sheets of Marlex mesh in layers, for the reconstruction of the chest wall with 3 or more rib's defect, but if it is more small defect, we use the cross suture method. The cross suture is very easy and effective method to maintain the stability of small chest wall defect.

[Retroperitoneal laparoscopic pelvic lymphadenectomy for patients with prostate cancer]

Between February 1994 and February 1995, we performed retroperitoneal laparoscopic pelvic lymphadenectomy on 7 patients with prostate cancer between 63 and 76 years old, consisting of 6 patients with clinical stage B2, and 1 patient with stage C. Retroperitoneal laparoscopic procedures were performed under general anesthesia. First, the prevesical space was separated by a balloon dissector to create the working space. Then, three trocars were inserted into the retroperitoneal space at the lower abdominal midline. Except for the first patient, only two surgeons were needed to dissect the obturator lymph nodes, under 5 mmHg CO2 insufflation. The mean operating time was 133 minutes for bilateral lymphadenectomy. The mean number of removed lymph nodes was 4.8 on the left side and 4.2 on the right side. The estimated blood loss ranged from 10 to 66 ml. As none of the patients showed node involvement on the microscopic examination of the frozen section, they immediately underwent total prostatectomy. Additionally removed lymph nodes were 0.8 on the left side and 1.5 on the right side. As for intraoperative complications, endotidal CO2 was elevated in the first patient, but the other patients had no complications. Retroperitoneal laparoscopic pelvic lymphadenectomy is a safe and useful procedure, and may facilitate a lymphadenectomy better than a peritoneal procedure.

Antitumor activity and chemical modification of polysaccharides from niohshimeji mushroom, Tricholma giganteum

Two chemical modification procedures, Smith degradation and formolysis processes, were used in an attempt to improve the antitumor activity of water-soluble and water-insoluble polysaccharides prepared from the fruiting body of niohshimeji, Tricholoma giganteum. The chemically modified products were examined for their antitumor effects on Sarcoma 180 solid tumor implanted in mice. The following results were as follows: Some Smith degradation products, i.e., O-R-Flo-c-beta and O-R-FA-2 prepared from water-soluble polysaccharides, and O-R-FII-1 and O-R-FIII-2-c from water-insoluble polysaccharides, had higher antitumor activities than the original polysaccharides. None of the formolysis products, F-Flo-a, F-W-Flo-a, F-FA-3, F-W-FA-3 from water-soluble polysaccharides, and F-FII-2, F-W-FII-2, F-FIII-2-b, and F-W-FIII-2-b prepared from water-insoluble polysaccharides had improved antitumor activities.

Locomotion of neutrophil fragments occurs by graded radial extension

The only kinematic description of cell locomotion that relates the dynamics of actin filaments to whole cell movement is the graded radial extension (GRE) model for fish keratocytes, which glide without changing their shapes or sizes. To test whether the GRE model is applicable to other cell types, we analyzed the detailed shape changes during locomotion of heat-induced motile fragments of human polymorphonuclear leukocytes (PMNs). These fragments, called cytokineplasts, were loaded uniformly with a fluorescent cytoplasm-staining dye and their motility and shape changes were analyzed by fluorescence-video microscopy and digital image processing. Two-dimensional (2-D) analysis showed that cytokineplasts only changed their shapes and sizes slightly and apparently maintained their roughly circular shapes, whereas fluorescence-intensity analysis revealed distinct changes in their cytoplasmic thickness profiles. Furthermore, small structures on the cytoplasmic margins behaved as predicted by the GRE model, which therefore is probably also applicable to the parental PMNs, which show complex shape changes. This is the first indication that the GRE model operates in non-fish-keratocyte cells and may, therefore, be a universal model of cell locomotion.

The osmo-inducible gpd1+ gene is a target of the signaling pathway involving Wis1 MAP-kinase kinase in fission yeast

The gpd1+ gene of Schizosaccharomyces pombe encodes an isozyme of NADH-dependent glycerol-3-phosphate dehydrogenases that is involved in glycerol synthesis, whose expression is induced upon an upshift of the medium osmolarity. We provide evidence that this osmotic induction of gpd1+ in S. pombe is under the control of a MAP-signaling pathway involving the wis1+ gene-product, which is a homologue of MAP-kinase kinases. The results suggested that the gpd1+ gene is a downstream target of the osmosensing signaling that is transmitted through Wis1, thereby defects of either of these genes result in the similar phenotype, namely, osmosensitive for growth, because of the failure in accumulation of the intracellular osmoprotectant, glycerol.

Phosphotransfer circuitry of the putative multi-signal transducer, ArcB, of Escherichia coli: in vitro studies with mutants

Recently we demonstrated the occurrence of a novel device of signal transducers in Escherichia coli. This class of bacterial sensory kinases, typified by ArcB and BarA, possesses two phospho-donor (His) sites, together with a phospho-accepting (Asp) site. These multi-phosphorylation sites were suggested to make a phosphotransfer circuit. To clarify this complex circuitry, we carried out a series of in vitro assays involving a set of ArcB mutant proteins which have an amino acid substitution at each putative phosphorylation site (His-292, Asp-576 and His-717). By these in vitro phosphorylation and/or phosphotransfer assays, the followings were assessed: (i) ArcB autophosphorylation; (ii) ArcB-mediated phosphorylation of the cognate response regulator, ArcA; (iii) ArcB-mediated phosphorylation of its truncated form (ArcBc) encompassing only the C-terminal phosphorylation site (His-717); (iv) phosphotransfer from ArcBc to ArcA; and (v) phosphotransfer from ArcBc to ArcB. On the basis of these in vitro results, a complex circuitry was revealed for the signal transducer ArcB. This evidence obtained in vitro supports the view that ArcB can serve as a powerful device for not only propagating multi-signals, but also making up signalling networks, in ways more sophisticated than previously thought.

Osmoregulation of fission yeast: cloning of two distinct genes encoding glycerol-3-phosphate dehydrogenase, one of which is responsible for osmotolerance for growth

Many types of microorganisms, including both prokaryotes and eukaryotes, have developed mechanisms to adapt to severe osmotic stress. In this study, we isolated multicopy suppressor genes for a Schizosaccharomyces pombe mutant, which exhibited the clear phenotype of being osmosensitive for growth (Osms) on agar plates containing high concentrations of either non-ionic or ionic osmotic solutes. Two genes were thus identified, and each was suggested to encode an NADH-dependent glycerol-3-phosphate dehydrogenase (GPD), which is required for glycerol synthesis. The nucleotide sequences, determined for these genes (named gpd1+ and gpd2+, respectively), revealed that S. pombe has two distinct GPD isozymes. They are only 60% identical to each other in their amino acid sequences. One such isozyme, GPD1, was shown to be directly involved in osmoregulation, based on the following observations. (i) Expression of gpd1+ was regulated at the mRNA level in response to osmotic upshift. (ii) It was demonstrated that wild-type cells markedly accumulated internal glycerol under high-osmolarity growth conditions. (iii) delta gpd1 mutants, however, failed to do so even in a high-osmolarity medium, and thus exhibited an Osms phenotype. On the other hand, the gpd2+ gene was constitutively expressed at a particular low level, regardless of the osmolarity of the medium.

A rare case of cardiac sarcoidosis in a patient with progressive systemic sclerosis, Sjogren's syndrome, and polymyositis

A 56-year-old woman with overlap syndrome of progressive systemic sclerosis (PSS), Sjogren's syndrome, and polymyositis is reported. She developed complete atrioventricular (AV) block and progressive bilateral hilar adenopathy, and was diagnosed as having sarcoidosis by histological examination of the hilar lymph nodes biopsied thoracoscopically. Although coexistence of one or two autoimmune diseases with sarcoidosis is not uncommon, coexistence of three or more autoimmune diseases with sarcoidosis is rare. To our knowledge, the described case is the first case in which the three above-mentioned autoimmune diseases were accompanied by myocardial sarcoidosis.

Effects of long-term treatment with low-dose pravastatin on biliary lipid and bile acid composition in patients with nonfamilial hyperlipoproteinemia

We tested the possibility that pravastatin, a competitive inhibitor of hepatic hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase, would alter cholesterol saturation of gallbladder bile by decreasing its cholesterol saturation index and/or degree of fatty acyl chain unsaturation in lecithin. Eighteen patients with type IIa hyperlipoproteinemia were treated with pravastatin 10 mg/d for 12 months. Gallbladder bile samples were aspirated with a duodenal tube by stimulating gallbladder contraction with intramuscular administration of cerulein before and after treatment. Serum cholesterol level was significantly reduced by 20% after 3 months, and this level was maintained after 12 months. In contrast, the cholesterol saturation index of gallbladder bile was not altered after 3 months (1.52 +/- 0.20 v 1.70 +/- 0.24), but it decreased significantly after 12 months (0.95 +/- 0.11, P < .01). The degree of fatty acyl chain unsaturation tended to decrease, although this was not statistically significant except for the decrease in molar percent of linoleate after 3 months. These findings suggest that long-term treatment with an inhibitor of HMG CoA reductase improves bile lithogenicity even at a comparatively low dose, and can decrease the incidence and complications of cholesterol gallstones.

p53 protein expression and p53 gene mutation in thymic epithelial tumors. An immunohistochemical and DNA sequencing study

p53 protein expression in 34 thymic epithelial tumors was examined immunohistochemically, and p53 gene mutation was detected in selected cases by DNA sequencing, using formalin-fixed and paraffin-embedded tissues. The tumors comprised 12 noninvasive thymomas, 9 invasive/metastatic thymomas, and 13 thymic carcinomas. All the tumors were immunoreactive for p53 protein. The p53-positive tumor cells in noninvasive thymoma were less than 10% (low expressor) in 7 cases and 10% to 50% (moderate expressor) in 5 cases. In invasive/metastatic thymoma, two were low expressors and seven were moderate expressors. In thymic carcinomas, there were nine moderate expressors and four high expressors (with > 50% positive cells). There was significant difference in p53 protein immunopositivity between thymic carcinoma and each of the noninvasive or invasive/metastatic thymomas. The DNA sequencing study confirmed the presence of p53 gene point mutation in all 10 cases examined, including three low expressors. These results suggest that p53 gene mutation is an early event in thymic tumorigenesis, and the p53 protein-positive cells increase with the progression of the tumor. Immunostaining reactivity of p53 may be a useful adjunct to differentiate thymic carcinoma from thymoma.

An Escherichia coli curved DNA-binding protein whose expression is affected by the stationary phase-specific sigma factor sigma S

From Escherichia coli, a DNA-binding protein that preferentially recognizes a curved DNA sequence was isolated and shown to correspond to one that has recently been reported as a binding protein for the replication origin of the E. coli chromosome, named Rob. Here, a rob promoter-lacZ transcriptional fusion was constructed on the chromosome, and used to demonstrate that the expression of rob is notably enhanced at the onset of stationary phase in Luria-broth and also under certain growth conditions in a minimal medium, such as glucose- and phosphate-starvation medium. It was further shown that this growth condition-dependent expression of rob is notably reduced in a null mutant for the stationary phase-specific sigma subunit of RNA polymerase, sigma s, although sigma s-independent expression of rob was significant during the logarithmic growth phase. Furthermore the rob null mutant was found to exhibit, as compared with the wild-type, an altered profile of protein synthesis, particularly at the very late stationary phase.

Gene activation by the Escherichia coli positive regulator OmpR: a mutational study of the DNA-binding domain of OmpR

The Escherichia coli DNA-binding protein, OmpR, is one of the best characterized of the bacterial positive regulators that enhance the transcriptional ability of RNA polymerase. OmpR, consisting of 239 amino acids, binds to specific sequences located upstream of the cognate ompC and ompF promoters. The C-terminal half of OmpR, consisting of about 120 amino acids, exhibits an inherent DNA-binding ability. To address the issue of DNA binding by OmpR, we selected a set of OmpR mutants, each of which has a single amino acid substitution in the C-terminal half of OmpR. In particular, we characterized a number of OmpR mutants which are defective in DNA binding and thereby result in an OmpF- OmpC phenotype. Among them, a putative positive control OmpR mutant was also obtained, which appears to be defective in phosphorylation-dependent transcriptional activation, but not in DNA binding. These results are discussed with general emphasis on DNA recognition by the E. coli family of OmpR-like regulatory proteins.