Sphingosine inhibits the synthesis of RNA primers by primase in vitro

We have previously shown the presence of sphingomyelin and sphingomyelinase in cell nuclei, suggesting that they may play a role in the intranuclear production of sphingosine, a potent bioactive molecule modulating diverse cellular functions. In the present study, the direct effects of sphingosine (C18:1) on the activity of DNA replication/repair polymerases were studied in vitro. Sphingosine had no effect on DNA polymerases alpha and beta and slightly inhibited DNA polymerases gamma, delta, and epsilon. In contrast, sphingosine strongly inhibited the activity of primase in a dose-dependent manner. On the other hand, dihydrosphingosine (C18:0), glycolipids, sphingomyelin, and ceramide had no effect on primase activity. Sphingosine equally inhibited the activity of primase complexed with DNA polymerase alpha, as well as its free form, with a Ki value of 4 microM. A gel-retardation analysis showed that the binding of primase with 32P-labeled template DNA was suppressed by sphingosine. Inhibition by sphingosine was competitive with the DNA template, but not with the substrate NTPs. After product analysis, a dose-dependent decrease in the amount of RNA primer products, consisting mainly of 10- and 11-mers, was observed in the presence of sphingosine, indicating that it inhibits the synthesis of RNA primers by primase. Sphingosine, however, had no effect on T7 RNA polymerase.

[Hemophagocytic syndrome observed in a patient with systemic lupus erythematosus]

A 52-year-old woman was admitted to our hospital because of a skin rash, high fever and myalgia. She had been diagnosed ten years ago by a dermatologist as having MCTD (mixed connective tissue disease). At the time of admission a diagnosis of active SLE was made by fulfilling four of the 1982 ARA criteria together with increasing levels of anti-DNA antibody and low levels of complements. Prednisolone (PSL) given orally in an initial dosage of 60 mg/day was effective during the first 6 weeks. Then a high fever, skin rash and pancytopenia appeared without active findings of SLE. Infection caused by bacteria, fungus or virus was suspected, but no infectious agent was present in cultures derived from blood or other sources. Antimicrobic drugs used were not effective at all. The clinical picture was suggestive of a drug allergy, but no causative drug was found. A diagnosis of hemophagocytic syndrome (HPS) was made because of the increased number of unusual hemophagocytic cells in the bone marrow. High levels of serum ferritin and neopterin, which are known to reflect macrophage activation, supported the diagnosis of HPS. HPS is characterized by activated phagocytosis presumably induced by hypersecretion of cytokines. Malignant lymphoma and infection are the two representative diseases which may cause HPS. Recently, an acute lupus HPS was reported in patients with active SLE. Here we reported a case of reactive HPS observed in a patient with SLE who had been receiving high dose PSL. Symptoms and findings of the patient gradually disappeared in several weeks after rapid reduction of the PSL dose.(ABSTRACT TRUNCATED AT 250 WORDS)

IFN-alpha inhibits antigen-induced eosinophil and CD4+ T cell recruitment into tissue

In a murine model of airway late phase reaction, we have previously shown that Ag-induced eosinophil recruitment into the tissue of sensitized mice is mediated by CD4+ T cells and IL-5. To determine whether IFN-alpha regulates Ag-induced eosinophil recruitment into tissue, we studied the effects of rIFN-alpha, endogenous IFN-alpha production induced by poly I.C, and anti-IFN-alpha mAb on the eosinophil infiltration of the trachea induced by Ag inhalation in mice. The i.p. administration of rIFN-alpha prevented Ag-induced eosinophil infiltration in the trachea of sensitized mice. In addition, the inhibitory effect of rIFN-alpha on Ag-induced eosinophil infiltration was not recovered by pretreatment with anti-IFN-gamma mAb. The administration of rIFN-alpha also inhibited Ag-induced CD4+ T cell infiltration in the trachea. However, the administration of rIFN-alpha did not significantly affect blood eosinophil counts nor the number of blood and splenic CD4+ T cells. On the other hand, pretreatment with anti-murine IFN-alpha mAb enhanced Ag-induced eosinophil and CD4+ T cell infiltration in the trachea. Finally, endogenous IFN-alpha/beta production induced by poly I.C also inhibited Ag-induced eosinophil infiltration in the trachea and this inhibition of the eosinophil infiltration was abrogated by pretreatment with anti-IFN-alpha/beta mAb. These results indicate that IFN-alpha suppresses Ag-induced eosinophil and CD4+ T cell recruitment into tissue.

[Imaging and clinical significance of hepatic portal venous gas seen in adult patients]

In 10 adult patients with hepatic portal venous gas (HPVG), the clinical significance of HPVG and the efficacy of X-ray computed tomography (CT) were evaluated. HPVG was associated with ischemic bowel disease (n = 3), trauma (n = 4), liver abscess (n = 1), sepsis (n = 1), and unknown etiology (n = 1). The diagnostic ability of CT for the detection of HPVG was far superior to that of plain abdominal radiograph. Of 9 patients who underwent CT, HPVG located in the left hepatic lobe in all patients, and also in right hepatic lobe in 7 patients. Gas could be recognized in the left lobe and the anterior segment of the right lobe more clearly than in the posterior segment of the right lobe because of its larger amount of intravenous collection. The mortality rate of our cases was 100%. Gas was demonstrated simultaneously in the portal vein radicles and hepatic veins on CT in 4 patients with no clinical evidence of sepsis, which suggested the possibility of intraparenchymal shift of gas from the portal vein into the hepatic vein. In a single case with sepsis, gas was noted in various vessels, including arteries, in addition to the portal venous system. The authors conclude that HPVG is still a grave sign in Japan and prompt appropriate treatment is required. CT may be of great value in the early detection of HPVG and may indicate its etiology.

Direct evidence of neuron impairment by oral infection with verotoxin-producing Escherichia coli O157:H- in mitomycin-treated mice

We developed a mouse model of acute encephalopathy induced by verotoxin 2 variant (VT2v)-producing Escherichia coli. Three-week-old mice were inoculated intragastrically with approximately 10(10) CFU of E. coli O157:H- strain E32511/HSC and simultaneously given an intraperitoneal injection of mitomycin (MMC; 2.5 mg/kg). Drinking water containing 5 g of streptomycin sulfate per liter was given ad libitum from 3 days before the infection. From 1 to 2 days after bacterial inoculation, clinical features including weight loss, weakness, and flaccid paralysis of the extremities developed, usually culminating in death within 4 days. Diarrhea was not observed during the course of disease. No mice died in the absence of streptomycin or MMC treatment for 2 weeks after the oral bacterial infection. Judging from the clinical course and the biochemical and histological examination, the cause of death was not likely to be attributable to renal failure or to a side effect of MMC. To better understand the cause of death, we examined the brain cortex and spinal cord of the moribund mice by electron microscopy. Mice showing mortal symptoms were given horseradish peroxidase intravenously. The tracer was present in the endothelial basal lamina, in the surrounding extracellular spaces, and even in the neuron fibers of the brain cortex. Furthermore, immunoreactivity of VT2v, proved by the use of rabbit anti-VT2 serum, was localized selectively in the damaged myelin sheaths of neuron fibers which were accompanied by edematous axons in the brain cortex and spinal cord. These findings strongly suggest that VT2v is toxic to both endothelial cells and neurons in the central nervous system and subsequently causes fatal acute encephalopathy.

[Changes in fatty acid composition, platelet aggregability and RBC function in elderly subjects with administration of low-dose fish oil concentrate and comparison with younger subjects]

Anti-thrombotic and anti-atherogenic effects of eicosapentaenoic acid (EPA) through the modulation of various cell functions related to thrombogenesis have been reported recently. We previously reported that the administration of EPA at low doses could more effectively elevate the plasma EPA concentration in elderly subjects than in younger ones. Magnetic resonance imaging examination of the brain often reveals lacunar lesions in elderly subjects without any signs or symptoms of cerebrovascular diseases. In this study we clarified the effect of administration of low doses of fish oil concentrate on platelet and RBC function in elderly subjects, compared with younger subjects. Thirty six elderly subjects (mean age 78) without any signs or symptoms of cerebrovascular diseases, all receiving the same diet in the same lodging house for the aged, were divided into 3 groups. Different amounts of fish oil concentrate (0.25-0.5 g/day of EPA) were administered to the 3 groups, daily for more than 1 month. Changes of plasma fatty acid composition, platelet aggregability, whole blood viscosity and RBC deformability was examined before and after EPA administration. One month after EPA treatment, the plasma EPA content had increased dose dependently, with suppression of platelet aggregation and improvement of RBC function. In younger subjects receiving the same amount of EPA, the elevation of plasma EPA was less than that observed in the elderly. In summary, low dose EPA administration can improve the function of platelet and RBC to an anti-thrombotic state and would be useful to prevent the occurrence of cerebrovascular diseases in elderly subjects without any side effects.

p53 expression in myeloid cells of myelodysplastic syndromes. Association with evolution of overt leukemia

To assess p53 expression in the hematopoietic cells of the bone marrow in premalignant as well as malignant conditions, we examined immunohistochemically bone marrow biopsies from patients with myelodysplastic syndromes (MDS, n = 51), acute myeloid leukemia (n = 42) and as a nonneoplastic condition, aplastic anemia (n = 20) and samples from individuals who had no hematological disorder (control, n = 12). Nuclear accumulation of p53 protein was found in seven of 51 patients with MDS (14%) and two of 42 acute myeloid leukemia patients (5%), whereas patients with aplastic anemia and control subjects were uniformly negative for p53 protein. In the bone marrow of patient with MDS, p53-positive cells constituted about 5 to 30% of the total bone marrow cells. Two-color immunohistochemical analysis revealed that the p53-positive cells were also positive for the myeloid cell marker. Half of the MDS cases that evolved to overt leukemia (seven of 14) exhibited positive p53 reaction in the bone marrow at the time of initial diagnosis. This frequency (50%) was significantly higher than that in de novo acute myeloid leukemia cases. All of the seven MDS cases that exhibited p53 expression at the time of initial diagnosis developed overt leukemia later, and p53 expression was maintained throughout the progression of MDS. The results suggest that p53 mutations that occur in the myeloid cells in MDS may confer a growth advantage to these cells resulting in the progression to overt leukemia. Thus, immunohistochemical examination for p53 is very useful for predicting the evolution to overt leukemia from MDS.

IFN-alpha inhibits antigen-induced eosinophil and CD4+ T cell recruitment into tissue

In a murine model of airway late phase reaction, we have previously shown that Ag-induced eosinophil recruitment into the tissue of sensitized mice is mediated by CD4+ T cells and IL-5. To determine whether IFN-alpha regulates Ag-induced eosinophil recruitment into tissue, we studied the effects of rIFN-alpha, endogenous IFN-alpha production induced by poly I.C, and anti-IFN-alpha mAb on the eosinophil infiltration of the trachea induced by Ag inhalation in mice. The i.p. administration of rIFN-alpha prevented Ag-induced eosinophil infiltration in the trachea of sensitized mice. In addition, the inhibitory effect of rIFN-alpha on Ag-induced eosinophil infiltration was not recovered by pretreatment with anti-IFN-gamma mAb. The administration of rIFN-alpha also inhibited Ag-induced CD4+ T cell infiltration in the trachea. However, the administration of rIFN-alpha did not significantly affect blood eosinophil counts nor the number of blood and splenic CD4+ T cells. On the other hand, pretreatment with anti-murine IFN-alpha mAb enhanced Ag-induced eosinophil and CD4+ T cell infiltration in the trachea. Finally, endogenous IFN-alpha/beta production induced by poly I.C also inhibited Ag-induced eosinophil infiltration in the trachea and this inhibition of the eosinophil infiltration was abrogated by pretreatment with anti-IFN-alpha/beta mAb. These results indicate that IFN-alpha suppresses Ag-induced eosinophil and CD4+ T cell recruitment into tissue.

V gene analysis of anti-cardiolipin antibodies from (NZW x BXSB) F1 mice

In (NZW x BXSB) F1 (W/B F1) male mice, systemic lupus-like disease, thrombocytopenia and coronary vascular disease with myocardial infarction occur, due to the presence of platelet-associated antibodies, anti-platelet antibodies and anti-cardiolipin antibodies (aCL). We developed monoclonal aCL and analysed the specificity of aCL. In the W/B F1 mice, there are aCL with pathogenic properties, which have an IgG isotype and reveal a cofactor-dependent binding to CL, binding activity to platelets, and lupus anti-coagulant (LA) activity. Here, we analysed the usage of VH and V kappa genes of six aCL, including two pathogenic aCL, from W/B F1 mice, in an attempt to address the question of whether or not aCL with pathogenic properties use restricted Ig V genes. Sequence analysis of VH and V kappa genes of aCL showed that the pathogenic aCL had VHJ558 and V kappa 21 or V kappa 23 genes, whereas the other aCL without pathogenic features used mainly the 7183 VH family and the random V kappa gene group. However, two pathogenic aCL showed a 86.6% homology with the IgV region, each other, indicating that they were not closely related clones. Thus, these findings suggest the possibility that usage of Ig VH genes in pathogenic aCL is not random, but that there may exist a few epitopes of antigen recognized by the pathogenic aCL.

Immunolocalization of platelet-derived growth factor, transforming growth factor-beta, and fibronectin in acute megakaryoblastic leukemia manifesting tumor formation

Acute megakaryoblastic leukemia (AMKL) manifesting myelofibrosis and tumor formation in the liver with marked increase of reticulin is described. The megakaryoblastic nature of the leukemic cells of the bone marrow and the hepatic tumor nodule was established by positive immunohistochemical stains for CD41a and CD41b on frozen tissue sections. Immunolocalization of the platelet-derived growth factor (PDGF) protein and transforming growth factor (TGF)-beta protein also was demonstrated in the leukemic cells of the bone marrow and the hepatic tumor. Further, the deposition of fibronectin that has been known as the ligand of CD41a molecule and collagen types I and IV were recognized in the extracellular matrix of the bone marrow and the hepatic tumor. These results suggest that specific expression of growth factor proteins by the leukemic cells may selectively regulate the fibrosis of the bone marrow as well as the tumor formation of AMKL. The expression of adhesion molecules and growth factor proteins by the leukemic cells and the deposition of extracellular matrix are discussed in relation to the myelofibrosis as well as the tumor-forming nature of AMKL.

Effect of glutamine and chemotherapy on protein metabolism in tumor-bearing rats

Supplemental glutamine prevents gut atrophy and enhances muscle protein synthesis in septic rats. This study investigated the effect of glutamine administration and mitomycin C treatment on protein turnover in tumor-bearing rats. AH109A rat ascites hepatoma cells (2 x 10(6)) were subcutaneously implanted in the back of male Donryu rats (n = 32, body weight 150-200 g) on Day 0. The animals were then fed rat chow ad libitum for 10 days. On Day 10, the rats were catheterized for TPN and randomized into four groups according to diet and treatment. The groups were: (i) standard total parenteral nutrition (STPN) + saline; (ii) glutamine-supplemented TPN (GTPN) + saline; (iii) STPN+mitomycin C (MMC); (iv) GTPN+MMC. GTPN was isocaloric (250 kcal/kg/day) and isonitrogenous (1.5 gN/kg/day) with STPN. The animals were maintained on TPN for 5 days and received mitomycin C (0.5 mg/kg) via the catheter every day. On the fifth day of TPN, [1-14C]leucine was given via a 5-hr continuous infusion (2.0 microCi/hr/rat) to determine the fractional synthesis rate of muscle, gut mucosa, liver, and tumor. Also, endogenous leucine production (not equal to whole body protein breakdown rate) was calculated. Body weight loss during TPN was reduced with GTPN. GTPN enhanced muscle FSR in untreated animals (STPN: 10.8 +/- 8.7%/day vs GTPN: 14.7 +/- 0.6%/day, P < 0.05) and in mitomycin C-treated animals (STPN+MMC: 9.6 +/- 0.9%/day, GTPN+MMC: 12.0 +/- 0.8%/day, P < 0.05). The whole body protein breakdown rate was reduced with GTPN. Mitomycin C reduced the mucosal fractional synthesis rate and GTPN did not prevent this reduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of the development of murine myeloid leukemia with granulocyte colony-stimulating factor by inducing apoptosis of leukemic cells

We studied the antileukemic effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) by using a radiation-induced murine myeloid leukemia cell line C2M-A5. Intravenous inoculation of C2M-A5 cells into C3H/He mice resulted in the development of myeloid leukemia. However, the leukemic death of the mice was completely suppressed by the subcutaneous injections of rhG-CSF. In order to clarify the mechanism of the suppression, effects of rhG-CSF on C2M-A5 cells were studied in vitro. While C2M-A5 cells grew exponentially in the absence of rhG-CSF, the viability, the growth, and the self-renewal capacity of C2M-A5 cells were all suppressed in cultures in the presence of rhG-CSF. Preincubation with rhG-CSF for 48 h deprived C2M-A5 cells of the ability to induce leukemia in syngeneic mice. Morphological examination revealed the appearance of apoptotic changes of C2M-A5 cells in cultures containing rhG-CSF over the 2-day incubation period. In gel electrophoresis, the DNA from C2M-A5 cells incubated with rhG-CSF for 48 h showed a ladder of degradated DNA bands compatible with apoptosis. From these results, we concluded that the apoptosis of C2M-A5 cells played a key role in the antileukemic effect of rhG-CSF.

Autonomy of expression of epidermis-specific genes in the ascidian embryo

An example of developmental autonomy, assessed at the level of expression of tissue-specific genes, was characterized in this study. cDNA clones that corresponded to two different epidermis-specific genes (HrEpiA and HrEpiB) of the ascidian Halocynthia roretzi were isolated. Transcripts of both genes first appeared around the time of gastrulation, suggesting zygotic expression. In the case of HrEpiA, transcripts became undetectable after metamorphosis had begun, while transcripts of HrEpiB were still detectable in juveniles after metamorphosis. In situ hybridization analysis using HrEpiA and B probes gave the following results. (1) All types of partial embryo that originated from blastomeres with epidermal fate from two-, four-, and eight-cell embryos expressed these two epidermis-specific genes. (2) When cleavage was blocked by treatment with cytochalasin B at the one-cell stage, the cleavage-arrested one-celled embryos expressed the two genes. (3) Even when blastomeres with epidermal fate were isolated from two-, four-, and eight-cell embryos and the division of the blastomeres was arrested immediately after isolation, they expressed the two specific genes. These results suggest that the epidermal lineage in the early ascidian embryo is a developmental system with considerable self-sustainability.

Primary empty sella in association with superior sagittal sinus thrombosis and dural arteriovenous malformation. Case report

A 61-year-old woman under treatment with oral medroxyprogesterone acetate following surgery for breast cancer developed diplopia and papilledema due to raised intracranial pressure (ICP). Radiological studies disclosed an empty sella turcica, a dural arteriovenous malformation (AVM), and superior sagittal sinus thrombosis. The sinus thrombosis was considered to have been a side effect of the medroxyprogesterone acetate medication. The association between a primary empty sella and raised ICP is briefly discussed, along with the cause-and-effect relationship between a dural AVM and venous sinus thrombosis.

Basal magnocellular and pontine cholinergic neurons coexpress FGF receptor mRNA

By in situ hybridization histochemistry, fibroblast growth factor receptor gene (flg)-expressing neurons were newly identified in the basal magnocellular nuclei (the vertical and horizontal limbs of the diagonal band, and Meynert's nucleus). The present study also confirmed flg localization in the laterodorsal tegmental nucleus and the pedunculopontine tegmental nucleus of the pons. Immuno- and in situ hybridization histochemistry on the same sections demonstrated that choline acetyltransferase and flg were colocalized in single neurons of the diagonal band, Meynert's nucleus and the pontine tegmental areas. The results suggest that a significant number of the basal magnocellular and a majority of the mesopontine cholinergic neurons are directly affected by fibroblast growth factors (FGF) via FGF receptor gene.

Ectopic gastric mucosa in the upper esophagus: detection and radiographic findings

PURPOSE

To detect and characterize the appearance of islands of ectopic gastric mucosa in the upper esophagus at routine examination of the upper gastrointestinal (GI) tract.

MATERIALS AND METHODS

Well-distended upper esophagus was documented with spot radiographs obtained with routine double-contrast examination performed after administration of high-density barium in nine patients. Detected lesions were confirmed by means of endoscopy and biopsy.

RESULTS

Twelve lesions were detected. Radiographic findings were characterized by either a discrete, shallow depression surrounded by a subtle, rimlike elevation on double-contrast images or by a pair of small indentations on the same wall on full-column, single-contrast images at the level of the thoracic inlet. Endoscopic examination revealed well-circumscribed areas of reddish mucosa located 15-26 cm from the incisors.

CONCLUSION

Ectopic gastric mucosa in the upper esophagus is easily demonstrated at routine examination of the upper GI tract. Diagnosis can be based on location and characteristic radiographic appearance.

[New endoscopic laser treatment for unilateral vocal cord paralysis after pulmonary resection]

In two patients who had developed aspiration due to left recurrent laryngeal nerve injury during radical resection for lung cancer, low power Nd:YAG laser irradiation of the paralyzed vocal cord was performed through a bronchofiberscope. With irradiation, the paralyzed vocal cords of both patients swelled and became fixed at the median portion of the glottis. Thereafter, aspiration disappeared. Thus, this new application of Nd:YAG laser irradiation is apparently quite useful in treating aspiration due to unilateral vocal cord paralysis immediately after pulmonary resection.

Enhanced arterial intimal thickening after balloon catheter injury in diabetic animals accompanied by PDGF beta-receptor overexpression of aortic media

Cultured aortic smooth muscle cells (SMC) of diabetic rats and rabbits, which overexpress platelet-derived growth factor (PDGF) beta-receptor compared with controls, have a unique phenotype. In this study we report on the PDGF beta-receptor overexpression in aortas of diabetic animals and the increased intimal thickening of carotid arteries in diabetic rabbits after balloon catheter injury compared with that in controls. In diabetic aortas with no treatments of balloon catheter injury, intimal thickening was not observed in spite of the overexpression of PDGF beta-receptor, indicating that the growth property of medial SMC in diabetic aortas was changed before the intimal thickening could take place. PDGF is known to be the main contributor to the intimal thickening induced by balloon catheter injury, which is one of several forms of arterial injuries. Intimal thickening after balloon catheter injury in diabetic rabbits increased compared with that in controls. These results imply that PDGF beta-receptor overexpression of SMC in medial layers plays an important role in intimal thickening in the formation of advanced diabetic macroangiopathy.

[The morphological study of cerebrospinal fluid drainage at monkey arachnoid granulations]

It is generally accepted that the arachnoid granulations play an essential role in the drainage of the cerebrospinal fluid (CSF) into venous system, but there is continuing in controversy as to the morphological features of their functions. The present study was undertaken to investigate the structure and function of monkey arachnoid granulations under the increased pressure of subarachnoid space by light, scanning (SEM) and transmission (TEM) electron microscopy. Granulations were classified into three types by surface endothelial morphology. They were, 1) a granulation covered with bulged endothelium only, 2) a granulation covered with flatten endothelium only, and 3) a granulation covered with both two previous mentioned endothelia. Type 1) and 2) were spherical or hemispherical in shape. Type 3) granulations were lobulated, having the flatten endothelium at the constricted portion and the bulged endothelium in the other major portion. Three kinds of mechanisms for CSF drainage at arachnoid granulations ("closed system", "open system" and "temporary vacuolar transcellular channel") were proved to exist concurrently, because morphological criteria findings of each mechanism were observed in the same specimen. So, we proposed that these arachnoid granulations should be called "arachnoid granulations complexs".

Substrate specificity of Streptomyces beta-xylanase toward glucoxylan

To discover the specificity of Streptomyces beta-xylanase toward xylan having glucose stubs, glucoxylan was prepared by the hydrogenation of cotton-seed cake glucuronoxylan. The glucoxylan was hydrolyzed by the beta-xylanase of Streptomyces olivaceoviridis E-86, and three kinds of glucoxylo-oligosaccharides were isolated from the hydrolysate by chromatographies on a charcoal column, preparative paper partition, and a Toyopearl HW-40F column. The isolated oligosaccharides had the structures of 2(3)-alpha-glucopyranosylxylotriose, 2(3)-alpha-(4-O-methyl-glucopyranosyl)xylotriose and 2(4)-alpha-glucopyranosylxylotetraose. From the structure of the above oligosaccharides and the results of our previous studies, we suggest that the specificity of Streptomyces beta-xylanase toward glucose stubs is the same as that toward glucuronic acid stubs, but differs considerably from that toward arabinose stubs.