Activation of mouse peritoneal macrophages by synthetic glyceroglycolipid liposomes

Summary Liposomes composed of chemically synthesized glyceroglycolipids, such as 1,2-dipalmityl-[-cellobiosyl-(1 3)]-glycerol (Cel-DAG), 1,2-dipalmityl-[-lactosyl-(1 3)]-glycerol, or 1,2-dipalmityl-[-maltosyl-(1 3)]-glycerol, were found to enhance protective immunity against transplantable tumor cells (sarcoma 180) in ICR mice. Peritoneal exudate cells prepared from mice treated in vivo with Cel-DAG showed cytostatic activity in vitro against the mouse leukemia cell line, EL-4. Adherent cells separated from this preparation showed similar activity. Peritoneal cells from polypeptone-injected mice acquired appreciable cytostatic activity when incubated in vitro in the presence of glyceroglycolipid liposomes. The adherent cell fraction alone showed rather weak cytostatic activity when pretreated with the glyceroglycolipids, and full activity was restored by supplementing with the nonadherent cell fraction. The ability of glycolipids to induce tumoricidal effects was affected by cholesterol content: with increasing cholesterol content, the activities decreased. Cholesterol-free glycolipid liposomes were taken more efficiently by macrophages than cholesterol-containing liposomes. Cholersterol modifies the surface property of glyceroglycolipid liposomes. Activation of macrophages is responsible for enhancement of protective immunity against tumor cells by injection of these glycolipids in vivo.This work was supported in part by Grants-in-Aid (Nos. 58010010, and 59870076) for Scientific Research from the Ministry of Education, Science and Culture of Japan     

The effect of chemicals on the activity of deglycosylated Aureobasidiumβ-fructofuranosidases

The effects of chemicals such as metal ions and typical organic enzyme inhibitors on the activity of deglycosylated β-fructofuranosidases ( P -1 and P -2) from Aureobasidium were observed and compared with those of native enzymes. P -1 and P -2 enzymes became sensitive to metal ions, such as Fe²⁺, Co²⁺, Ni²⁺ and Al³⁺, after deglycosylation. The enzymes were also inhibited by a sulphydryl reagent (monoiodoacetic acid), a peptide-hydrolysing reagent (hydroxylamine) and chelating reagents (sodium citrate, EDTA and sodium azide) after deglycosylation. The importance of deglycosylation for the determination of the true characteristics of the enzymes against chemicals is discussed.     

Purification and properties of extracellularβ-fructofuranosidases fromAureobasidium sp. ATCC 20524

Summary Two extracellular -fructofuranosidases (E-1 andE-2) fromAureobasidium sp. ATCC 20524, producing 1-kestose (1^F--fructofuranosyl-sucrose) from sucrose, were purified to homogeneity. Molecular weights of the enzymes were estimated to be about 304000 (E-1) and 315000 (E-2) Da by gel filtration. The enzymes contained 33% (w/w) (E-1) and 27% (w/w) (E-2) carbohydrate. TheK _m values for sucrose ofE-1 andE-2 andE-2 were 0.34 and 0.28 M, respectively. were 0.34 and 0.28 M, respectively. The enzymatic profiles of these enzymes were almost identical to intracellular enzymesP-1 andP-2 except for the differences in carbohydrate content andK _m values ofE-2 andP-2.     

Conversion of the Extracellular Dextransucrase Isoenzymes from Leuconostoc mesenteroides NRRL B-1299

Effect of oxygen tension on l-lysine, l-threonine and l-isoleucine accumulation was investigated. Sufficient supply of oxygen to satisfy the cell’s oxygen demand was essential for the maximum production in each fermentation. The dissolved oxygen level must be controlled at greater than 0.01 atm in every fermentation, and the optimum redox potentials of culture media were above ?170 mV in l-lysine and l-threonine and above ?180 mV in l-isoleucine fermentations. The maximum concentrations of the products were 45.5 mg/ml for l-lysine, 10.3 mg/ml for l-threonine and 15.1 mg/ml for l-isoleucine. The degree of the inhibition due to oxygen limitation was slight in the fermentative production of l-lysine, l-threonine and l-isoleucine, whose biosynthesis is initiated with l-aspartic acid, in contrast to the accumulation of l-proline, l-glutamine and l-arginine, which is biosynthesized by way of l-glutamic acid.     

Self-controllable prodromal symptoms of syncope attributed to carotid sinus syndrome during the end stage of cancer: a case report

Background

Carotid sinus syndrome (CSS) can cause prodromal symptoms of syncope such as dizziness and nausea. Patients with end-stage cancer lose self-efficacy associated with reduced activities of daily life (ADL). Herein, we report a case of end-stage cancer in which self-efficacy was enhanced as the patient gained self-control of prodromal symptoms of syncope.

Case presentation

A 70-year-old patient with end-stage esophageal cancer and enlarged supraclavicular lymph nodes developed CSS. The CSS was a mixed type with both bradycardia and decreased blood pressure, accompanied by prodromal symptoms prior to syncope episodes. The patient incidentally discovered that he could decrease the duration of symptoms by contracting the muscles in his hands and legs. By applying this coping method at the onset of prodromal symptoms, he was also able to reduce the severity and duration of symptoms, which resulted in enhanced self-efficacy. As a result, the frequency of prodromal symptoms also decreased even though ADL improved.

Conclusion

This patient was diagnosed with vasoinhibitory-predominant mixed-type CSS. The coping method the patient developed seemed to avoid the onset of abrupt blood pressure decrease via peripheral vascular constriction action. Achievement of adequate coping such as self-control of prodromal symptoms enabled our patient to improve his self-efficacy even at the end stages of cancer. This case of enhanced self-efficacy could possibly illustrate a placebo effect for prevention of recurrence.

     

Interaction of plexin-B1 with PDZ domain-containing Rho guanine nucleotide exchange factors

The Rho family GTPase has been implicated in plexin-B1, a receptor for Semaphorin 4D (Sema4D), mediating signal transduction. Rho may also play a function in this signaling pathway as well as Rac, but the mechanisms for Rho regulation are poorly understood. In this study, we have identified two kinds of PDZ domain-containing Rho-specific guanine nucleotide exchange factors (RhoGEFs) as proteins interacting with plexin-B1 cytoplasmic domain. These PDZ domain-containing RhoGEFs showed significant homology to human KIAA0380 (PDZ-RhoGEF) and LARG (KIAA0382), respectively. Both KIAA0380 and LARG could bind plexin-B1 and a deletion mutant analysis of plexin-B1, KIAA0380 and LARG revealed that KIAA0380 and LARG bound plexin-B1 cytoplasmic tail through their PDZ domains. The tissue distribution analysis indicated that plexin-B1 was co-localized with KIAA0380 and LARG in various tissues. Immunocytochemical analysis showed that LARG was recruited to plasma membrane by plexin-B1. These results suggest that PDZ domain-containing RhoGEFs play a role in Sema4D-plexin-B1 mediating signal transduction.     

Effect of reduced bronchial circulation on lung fluid flux after smoke inhalation in sheep

We determined the effect of reduced bronchialblood flow on lung fluid flux through changes in lung lymph flow, lungwet weight-to-dry weight (wet/dry) ratios, and pulmonary microvascularreflection coefficient (). In the first of two surgical procedures,Merino ewes (n = 21) were surgicallyprepared for chronic study. Five to seven days later, in a secondoperation, the bronchial artery of the injection group(n = 7) was ligated, and 4 ml of 70%ethanol were injected into the bronchial artery to cause sclerosis of the airway circulation. In the ligation group(n = 7), only the bronchial artery wasligated. In the sham group (n = 7),the bronchial artery was surgically exposed but left intact withoutligation or ethanol injection. One day after these operations theanimals received a tracheotomy and 48 breaths of cotton smoke. Thevalue of  was determined at two points: 24 h before the secondsurgical procedure and 24 h after smoke inhalation. Lung lymph flow,blood-gas parameters, and hemodynamic data were measured every 4 hafter injury. At the end of investigation, samples of lung were taken for determination of blood-free wet/dry ratio. In the sham group, inhalation injury induced a gradual increase in pulmonary vascular resistance and lung lymph flow, which was associated with deterioration of oxygenation. Reduction of the bronchial blood flow attenuated thesepathophysiological changes, and the degree of this attenuation wasgreater in the injection group than in the ligation group. The value of was significantly higher after smoke inhalation in the injectiongroup compared with the sham group (0.77 ± 0.04 vs. 0.61 ± 0.03, means ± SE) at 24 h. The mean wet/dry ratio value of theinjection group animals was 30% less than that of the sham group. Ourdata show that the bronchial circulation contributes to edema formationin the lung occurring after acute lung injury with smoke inhalation.

     

Chelating Compound,Chrysoidine, Is More Effective in Both Antiprion Activity and Brain Endothelial Permeability Than Quinacrine

1. As an extension of our previous study of quinacrine and its derivatives, chelating chemicals were screened to obtain more effective, better brain-permeable antiprion compounds using either prion-infected neuroblastoma cells or brain capillary endothelial cells. 2. Eleven chemicals were found to have antiprion activity. Most of them shared a common structure consisting of benzene or naphthalene at either end of an azo bond. Structure–activity data suggest that chelating activity is not necessary but might contribute to the antiprion action. 3. Chrysoidine, a representative compound found here, was about 27 times more effective in the antiprion activity and five times more efficiently permeable through the brain capillary endothelial cells than quinacrine was. 4. These chemicals might be useful as compounds for development of therapeutics for prion diseases.     

An Inhibitory Role of Nitric Oxide in the Dynamic Regulation of the Blood-Brain Barrier Function

1. The present study aimed at elucidating the effect of nitric oxide (NO) on blood-brain barrier (BBB) function with mouse brain capillary endothelial (MBEC4) cells. 2. Histamine (20–100 μM) evoked NO production (1.6–7 μM) in MBEC4 cells in a dose-dependent manner. 3. The permeability coefficient of sodium fluorescein for MBEC4 cells and the cellular accumulation of rhodamine 123 in MBEC4 cells were increased dose-dependently by the addition of NO solutions (14 and 28 μM) every 10 min during a 30-min period. 4. The present study demonstrated that NO increased the permeability and inhibited the P-glycoprotein efflux pump of brain capillary endothelial cells, suggesting that NO plays an inhibitory role in the dynamic regulation of the BBB function.