Localization and synthesis of acetylcholine in human leukemic T cell lines

In order to clarify the origin of acetylcholine (ACh) in human blood, we measured the content and synthesis activity of ACh in several human leukemic cell lines. The intracellular ACh content determined by a specific and sensitive radioimmunoassay in the human leukemic T cell lines, HSB-2, MOLT-3, and CEM, was 79.6, 36.2, and 9.5 pmol/10(6) cells, respectively. These values were 9-70-fold higher than those of other cell lines, including a helper T cell line, Jurkat. Stimulation of HSB-2 and MOLT-3 by phytohemagglutinin (PHA) increased both the intracellular content and release of ACh into the culture medium, but did not influence the intracellular content and release of ACh in CEM. ACh synthesis activity was found in all the T cell lines tested. Bromoacetylcholine (100 microM), a choline acetyltransferase (ChAT) inhibitor, and bromoacetyl-L-carnitine (100 microM), a carnitine acetyltransferase (CarAT) inhibitor, decreased ACh-synthesizing activity in MOLT-3, and HSB-2 and CEM, by about 50% and 30%, respectively, indicating that both ChAT, and to a lesser extent CarAt, are involved in ACh synthesis in T cells. These results suggest that T lymphocytes have the potential to synthesize and release ACh, which may play a role in regulating T cell-dependent immune responses.

Postnatal changes in activation of polyunsaturated fatty acid, acylation of lysophosphoglyceride, and phosphorylation of diacylglycerol in cortical gray matter of rat cerebrum

Activation of polyunsaturated fatty acid, acylation of lysophosphoglyceride, and phosphorylation of diacylglycerol in postnatal developing rat cerebrum were studied in vitro, using cortical gray matter homogenates. The rate of n-3 and n-6 fatty acid activation was maximal at ten days after birth and minimal at adulthood. Acylation of lysophosphoglyceride was most active at the neonatal stage and gradually decreased with age. In addition, the amount of phosphatidic acid formed from 1, 2-dioleoyl-glycerol was also maximum at the neonatal stage, and then gradually decreased. These results suggest that the specific activity of glycerolipid synthesis in cortical gray matter declines during postnatal development.

'Medial defects' in the prenatal human cerebral arteries: an electron microscopic study

BACKGROUND AND PURPOSE

Fine structural studies were performed to investigate the histogenesis of human intracranial arteries. Special attention was paid to whether "medial defects" exist in these arteries.

METHODS

Segments of the intracranial extracerebral arteries of normal human embryos (n=6) were examined with transmission electron microscopy.

RESULTS

Focal defects of the medial smooth muscle cells were disclosed at every bifurcation of the developing arteries. This configuration persisted until the arteries obtained enough muscle coat. These areas, in which an absence of medial smooth muscle cells (ie, a medial defect) existed, were occupied by fibrous connective tissues of elastin and collagen.

CONCLUSIONS

The medial defect observed at the arterial bifurcation of the embryos seems to be a development process that accompanies human ontogenesis rather than a congenital anomaly, supporting a possible pathogenesis for intracranial saccular aneurysms.

[Evaluation of the retrosternal space and the retrocardiac space on normal left lateral radiographs of the chest]

Left lateral chest radiographs with normal studies were evaluated in 100 Japanese (50 females and 50 males) to compare the radiolucency of the retrosternal space (RSS) with that of the retrocardiac space (RCS) and to measure the RSS. In 56 (56%) cases, the RSS was equally radiolucent to the RCS. In 40 (40%) cases, the RSS was less radiolucent than the RCS (33 of 50 females and 7 of 50 males). The difference between the sexes was statistically significant (p = 0.0001). The RSS was more radiolucent than the RCS in only 4 (4%) males. Frontal chest radiographs of 50 females were classified into one of three groups (Small, Medium, or Large) depending on the size of soft tissue opacity of the breast. The differences between the radiolucency of the RSS and RCS were statistically significant between the Small and Medium and the Small and Large groups (both p < 0.0001). The strength of the relationship between the radiolucency and body-to-fat ratio was statistically significant (p = 0.0028). Results of data comparison between females and males remained significant when adjusted for differences in body-to-fat ratio (p < 0.0001). The distance on the chest radiograph from the sternum to the most anterior aortic border (the distance of RSS) could be measured on only 37 (37%) lateral chest radiographs, and the averages and standard deviations were as follows: 2.2 +/- 0.5 in all cases, 2.0 +/- 0.5 in females, and 2.4 +/- 0.5 in males. The difference between the sexes was statistically significant (p < 0.05). In conclusion, an RSS that is more opaque (less radiolucent) than the RCS is a frequent normal finding because of the opacity of the breast and fat tissue, especially in females, and the length of the RSS is shorter in females than in males.

[Juxtaglomerular cell tumor: a case report]

We report a case of juxtaglomerular cell tumor. A 17-year-old female complained of headache with severe hypertension, hypokalemia, and elevated level of plasma renin activity. Computerized tomographic (CT) scan revealed a slightly enhanced tumor at middle pole of right kidney. Angiography showed a hypovascular tumor. A renin secreting tumor of the right kidney was diagnosed and right nephrectomy was performed. The pathological findings showed a juxtaglomerular cell tumor. Postoperatively, prompt normalization of blood pressure and decrease of plasma renin activity level were found. This case was incorporated into a review of the 43 cases previously published and we discussed the clinical characteristics of juxtaglomerular cell tumor in this report.

Synthesis, structure and thermodynamic properties of 8-methylguanine-containing oligonucleotides: Z-DNA under physiological salt conditions

Various oligonucleotides containing 8-methylguanine (m8G) have been synthesized and their structures and thermodynamic properties investigated. Introduction Of M8G into DNA sequences markedly stabilizes the Z conformation under low salt conditions. The hexamer d(CGC[M8G]CG)2 exhibits a CD spectrum characteristic of the Z conformation under physiological salt conditions. The NOE-restrained refinement unequivocally demonstrated that d(CGC[m8G]CG)2 adopts a Z structure with all guanines in the syn conformation. The refined NMR structure is very similar to the Z form crystal structure of d(CGCGCG)2, with a root mean square deviation of 0.6 between the two structures. The contribution of m8G to the stabilization of Z-DNA has been estimated from the mid-point NaCl concentrations for the B-Z transition of various m8G-containing oligomers. The presence of m8G in d(CGC[m8G]CG)2 stabilizes the Z conformation by at least deltaG = -0.8 kcal/mol relative to the unmodified hexamer. The Z conformation was further stabilized by increasing the number of m8Gs incorporated and destabilized by incorporating syn-A or syn-T, found respectively in the (A,T)-containing alternating and non-alternating pyrimidine-purine sequences. The results suggest that the chemically less reactive m8G base is a useful agent for studying molecular interactions of Z-DNA or other DNA structures that incorporate syn-G conformation.

Acute hypoxic pulmonary vascular response does not accompany plasma endothelin-1 elevation in subjects susceptible to high altitude pulmonary edema

We have previously shown that high altitude pulmonary edema-susceptible subjects (HAPE-S) have an accentuated pulmonary vascular response to hypoxia. In this study, we investigated the relationship between plasma endothelin-1 (ET-1) levels and the acute hypoxic pulmonary vascular response in HAPE-S and control subjects. In six HAPE-S and seven healthy subjects, we evaluated acceleration time/right ventricular ejection time (AcT/RVET) using Doppler echocardiography, and measured plasma ET-1 levels by radioimmunoassay (RIA) before and after 5 minutes of breathing 10% oxygen. The HAPE-S showed a significantly increased pulmonary vascular response to hypoxia compared with healthy subjects. However, no statistically significant changes of plasma ET-1 levels were observed before and after hypoxia in both groups. We conclude that the increased pulmonary vascular response to acute hypoxia in HAPE-S may not be related to ET-1 release.

Age-related change of phosphatidylcholine hydroperoxide and phosphatidylethanolamine hydroperoxide levels in normal human red blood cells

The age-related occurrence of phosphatidylcholine hydroperoxide (PCOOH) and phosphatidylethanolamine hydroperoxide (PEOOH) in normal human red blood cells (RBC) was confirmed by using chemiluminescence detection-high performances liquid chromatography (CL-HPLC). The concentration (mean +/- S.D.) for the healthy young adult (22-27 of age, n = 20) was 93 +/- 17 pmol PCOOH and 121 +/- 20 pmol PEOOH/ml packed RBC, while for the aged adult (56-92 of age, n = 20) the peroxide content was significantly higher, 162 +/- 52 pmol PCOOH and 186 +/- 40 pmol PEOOH/ml packed RBC. These results indicate that oxidative stress occurs constantly on RBC, even in normal humans, and that the susceptivity significantly increases with age.

Bronchoalveolar lavage fluid findings in patients with chronic hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) infection has recently been incriminated as an aetiological agent in idiopathic pulmonary fibrosis. This study was performed to determine the cellularity and lymphocyte phenotypes of bronchoalveolar lavage (BAL) fluid in patients with chronic hepatitis C.

METHODS

BAL fluid and lavage lymphocyte subsets from 13 patients (10 men) with active chronic hepatitis C, diagnosed by sustained elevated serum glutamic pyruvic transaminase and typical histological findings in the liver, were analysed. Lavage findings in these patients were compared with those from 13 healthy volunteers (eight men) as controls.

RESULTS

There was no difference in total cell counts in lavage fluid between the two groups. Lavage lymphocyte and eosinophil numbers were increased in patients with chronic hepatitis C. Surface marker analysis of the lymphocyte populations showed increases in CD2, CD3, CD4, and HLA-DR. CD4/CD8 ratios were not different.

CONCLUSIONS

The numbers of lymphocytes and eosinophils in BAL fluid are increased in patients with chronic hepatitis C. These findings suggest that HCV infection may trigger alveolitis.

Deficient cerebellar long-term depression, impaired eyeblink conditioning, and normal motor coordination in GFAP mutant mice

Mice devoid of glial fibrillary acidic protein (GFAP), an intermediate filament protein specifically expressed in astrocytes, develop normally and do not show any detectable abnormalities in the anatomy of the brain. In the cerebellum, excitatory synaptic transmission from parallel fibers (PFs) or climbing fibers (CFs) to Purkinje cells is unaltered, and these synapses display normal short-term synaptic plasticity to paired stimuli in GFAP mutant mice. In contrast, long-term depression (LTD) at PF-Purkinje cell synapses is clearly deficient. Furthermore, GFAP mutant mice exhibited a significant impairment of eyeblink conditioning without any detectable deficits in motor coordination tasks. These results suggest that GFAP is required for communications between Bergmann glia and Purkinje cells during LTD induction and maintenance. The data support the notion that cerebellar LTD is a cellular mechanism closely associated with eyeblink conditioning, but is not essential for motor coordination tasks tested.

[Analysis of cells and proteins in bronchoalveolar lavage fluid]

We studied cells and proteins in bronchoalveolar lavage fluid examined at the First Department of Internal Medicine of Shinshu University Hospital between 1990 and 1994. The samples came from 21 healthy subjects and from 216 patients with various diseases. Lymphocyte counts were abnormally high in patients with bronchiolitis obliterans organizing pneumonia. Sjögren's syndrome, sarcoidosis and hypersensitivity pneumonitis. Neutrophil counts were very high in the patients with diffuse panbronchiolitis and in those with high-altitude pulmonary edema, and eosinophil counts were high in those with eosinophilic pneumonia. The CD4:CD8 ratio was significantly higher in the patients with stage I sarcoidosis than in the healthy subjects. The total protein concentration and the albumin concentration were significantly higher in the patients with eosinophilic pneumonia and in those with high-altitude pulmonary edema than in the healthy subjects, and these findings suggest that in those two conditions the permeability of the pulmonary microvasculature was abnormally high.

Effect of repeated administration of KT3-671, a nonpeptide AT1 receptor antagonist, on diurnal variation in blood pressure, heart rate, and locomotor activity in stroke-prone spontaneously hypertensive rats as determined by radiotelemetry

KT3-671, a nonpeptide AT1 receptor antagonist, was administered to 20-week-old stroke-prone spontaneously hypertensive rats (SHRSP) daily for 3 weeks. Its effects on systolic, mean, and diastolic arterial blood pressure (SAP, MAP, DAP), heart rate and locomotor activity were investigated with radiotelemetry. A clear diurnal variation in blood pressure, heart rate, and locomotor activity was observed in synchrony with the light cycle. KT3-671 at a daily dose of 10 mg/kg orally (p.o), produced a significant and consistent reduction in blood pressure, preventing the development of hypertension. KT3-671 reduced SAP more than DAP, suggesting that it may affect both vascular tone and cardiac output. Although KT3-671 did not affect diurnal rhythms in heart rate and locomotor activity, it did cause a slight but significant reduction in heart rate. The MAP determined 23 h after the administration of KT3-671 showed a significant reduction from the day 2 of therapy to the day 3 after discontinuation of therapy, suggesting a long duration of antihypertensive action. There was no rebound increase in blood pressure after discontinuation of KT3-671 therapy. These results suggest that KT3-671 may be potentially useful in the therapy of hypertension.

Eosinophil chemotactic activity in bronchoalveolar lavage fluid obtained from Toxocara canis-infected rats

We examined eosinophil chemotactic activity (ECA) in bronchoalveolar lavage fluid (BALF) obtained from rats infected with Toxocara canis. For 4 weeks after infection, the number of eosinophils was determined in peripheral blood and BALF. ECA was assayed using a microchemotaxis chamber. Eosinophils in peripheral blood and BALF increased markedly after infection, peaking at 12 days and 2 weeks, respectively. ECA in BALF also increased significantly and peaked 2 weeks after infection. Partial characterization revealed that ECA was heat labile, lipid soluble, and resistant to trypsin digestion. Two ECA peaks were identified by molecular sieve column chromatography: one near the egg albumin marker (MW 45,000) and the other observed after elution with quinacrine (MW 472.9). Treatment with a specific leukotriene (LT) B4 receptor antagonist (ONO-4057), a platelet activating factor (PAF) receptor antagonist (TCV-309), and an anti-interleukin (IL)-5 monoclonal antibody (TB13) significantly reduced the ECA, suggesting that LTB4, PAF, and IL-5 contribute to the accumulation of eosinophils in the lungs of rats infected with T. canis.

High phosphatidylcholine hydroperoxide level in plasma of guinea pigs with low and excess supplementation of ascorbic acid

Graded amounts (0, 50, 500 and 5,000 mg/liter) of ascorbic acid (AsA) were given in drinking water to guinea pigs for 21 days to prepare AsA-deficient, low-AsA, moderate-AsA and excess-AsA animals, and the plasma phospholipid hydroperoxide level and lipid concentration were quantitatively determined to investigate the antioxidant effect of AsA in vivo. Phosphatidylcholine hydroperoxide (PCOOH) was a predominant phospholipid hydroperoxide present in the plasma, and the PCOOH concentration was significantly higher in AsA-deficient, low-AsA and excess-AsA animals (80.4 nM, 54.8 nM and 42.2 nM, respectively) as compared with that in moderate-AsA animals (27.2 nM). Hyperlipidemic plasma characterized as high cholesterol and high triacylglycerol concentrations was confirmed in AsA-deficient animals. Molar ratios of plasma AsA and alpha--tocopherol against 10(4) moles of phospholipids were significantly lower in AsA-deficient and low-AsA animals (0.6-2.1 and 5.5-8.5, respectively) than in moderate-AsA and excess-AsA animals (14.2-18.0 and 11.2-11.9, respectively). In plasma, a high correlation coefficient (r = 0.979) was observed between PCOOH and AsA for which there was optimum AsA level to keep the low PCOOH and such correlation was stronger than that (r = 0.558) observed with alpha-tocopherol. The results indicated that AsA has an important function to control the phospholipid hydroperoxide level in plasma and that moderate supplementation of AsA is required to reveal its optimal antioxidant effect in vivo. The present study also showed that AsA-deficiency especially invites an increase in plasma PCOOH together with a hyperlipidemic state which are risk factors in developing atherogenesis.

Isolation and characterization of primitive hematopoietic progenitors of murine fetal liver

We have isolated hematopoietic progenitors from mouse fetal liver using a sequential protocol of density gradient centrifugation, panning, and cell sorting. Isolated AA4.1+Ly-6A/E+CD43++ cells with density ranging from 1.0631 to 1.0770 g/cm3 were 480- to 600-fold enriched for multipotential progenitors relative to unfractionated cells and showed 40 to 60% colony-forming efficiency. We then examined the effects of various cytokines on the colony formation from enriched fetal liver cells. Steel factor (SF), interleukin-3 (IL-3), IL-4, IL-6, IL-11, and granulocyte colony-stimulating factor (G-CSF) as single agents supported formation of significant numbers of colonies, but flt3/flk-2 ligand (FL) and IL-12 did not. When the cytokines were combined, FL, SF, IL-3, and IL-4 each synergized individually with IL-6, IL-11, IL-12, or G-CSF to support formation of various types of colonies. Next we analyzed the growth factor requirements for proliferation and differentiation of lymphohematopoietic progenitors by using the two-step methylcellulose culture assay we established recently. None of the early-acting factors were effective as a single agent, but combinations of SF or FL with IL-6, IL-11, or G-CSF were effective in supporting B cell potential of the primary colonies. Of these, the combination of FL plus IL-11 appeared to be the most effective.

[Two cases of primary Sjögren's syndrome with pulmonary involvement histopathological study of open-lung biopsy specimens]

We report two cases of primary Sjögren's syndrome with pulmonary involvement, in which open lung biopsies were done. The patient in the first case was a 58-year-old woman and the patient in the second case was a 54-year-old woman. Both patients were admitted to our hospital because of dry coughing and exertional dyspnea. Chest X-ray films and CT scans showed interstitial shadows in both cases and multiple bullae in the first case. Pulmonary-function tests showed decreased diffusing capacity, and examination of bronchoalveolar lavage fluid revealed increased percentages of lymphocytes. Open-lung biopsy specimens showed thickening of the alveolar septa and interstitial mononuclear cell infiltration, composed predominantly of lymphocytes, with lymphoid follicles in both cases, and peribronchiolar mononuclear cell infiltration in the first case. Therefore, the histopathological diagnosis was cellular interstitial pneumonia with lymphoid follicles. Both patients were treated with oral corticosteroids. Symptoms were relieved and laboratory findings improved.

Overexpression of occludin, a tight junction-associated integral membrane protein, induces the formation of intracellular multilamellar bodies bearing tight junction-like structures

Occludin is an integral membrane protein localizing at tight junctions with four transmembrane domains. When chicken occludin was overexpressed in insect cells by recombinant baculovirus infection, peculiar multilamellar structures accumulated in the cytoplasm. Partial isolation of these structures indicated that the introduced chicken occludin was highly enriched in these structures. Thin section electron microscopy revealed that each lamella was transformed from intracellular membranous cisternae whose luminal space was completely collapsed, and that in each lamella, outer leaflets of opposing membranes appeared to be fused with no gaps, like tight junctions. Furthermore, in the freeze-fracture replicas of these multilamellar structures, short tight junction-like intramembranous particle strands were occasionally observed, which were specifically labeled by anti-occludin mAb. These observations favor the idea that occludin plays a key role in the formation of tight junctions.

Selective Isolation of DNA or RNA Using Single-Stranded DNA Affinity Latex Particles

We developed latex particles with a diameter of about 0.22 µm on which single-stranded (ss) DNA was covalently coupled to select or enrich its complementary DNA or mRNA. DNA was first covalently coupled to the latex particles in the double-stranded (ds) form with both blunt and protruding ends. More than 80% of the dsDNA was coupled through the ssDNA stretch at its protruding end. The presence of NaCl in the immobilization reaction severely inhibited DNA from coupling to the particles. The particles were then treated with alkali or heated to denature the dsDNA and sedimented by a brief centrifugation to yield ssDNA immobilized particles. They allowed the selective and efficient isolation of a desired RNA from total cellular RNA.

Nonpeptide angiotensin II receptor antagonists: synthesis, biological activities, and structure-activity relationships of imidazole-5-carboxylic acids bearing alkyl, alkenyl, and hydroxyalkyl substituents at the 4-position and their related compounds

A series of imidazole-5-carboxylic acids bearing alkyl, alkenyl, and hydroxyalkyl substituents at the 4-position and their related compounds were prepared and evaluated for their antagonistic activities to the angiotensin II (AII) receptor. Among them, the 4-(1-hydroxyalkyl)-imidazole derivatives had strong binding affinity to the AII receptor and potently inhibited the AII-induced pressor response by intravenous administration. Various esters of these acids showed potent and long-lasting antagonistic activity by oral administration. The most promising compounds were (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (CS-866) and (pivaloyloxy)-methyl esters of 4-(1-hydroxy-1-methylethyl)-2-propyl-1-[(2'-1H-tetrazol-5- ylbiphenyl-4-yl)-methyl]imidazole-5-carboxylic acid (26c). A study involving stereochemical comparison of 26c with the acetylated C-terminal pentapeptide of AII was also undertaken.

beta-carotene as a high-potency antioxidant to prevent the formation of phospholipid hydroperoxides in red blood cells of mice

In order to investigate the antioxidant effect of beta-carotene in vivo, phospholipid hydroperoxides and beta-carotene isomers in red blood cells (RBC), plasma and tissue organelles were quantitatively measured after the oral administration of beta-carotene (94.8% all-trans-beta-carotene) to mice. Three groups of 24 mice each were fed for 1 week on a semisynthetic diet supplemented with either 0.6% or 3.0% beta-carotene/diet or maintained on a control (beta-carotene-unsupplemented) diet. The RBC phospholipid hydroperoxides showed a significant decrease followed by an increase of beta-carotene intakes; i.e., 201, 16 and 4 pmol of phosphatidylcholine hydroperoxide/ml packed RBC, and 108, 22 and 8 pmol of phosphatidylethanolamine hydroperoxide/ml packed RBC, in the mice given the control diet, 0.6% carotene diet and 3.0% carotene diet, respectively. The RBC beta-carotene increased from 14 to 43 pmol/ml packed RBC as followed by the increase of beta-carotene intakes. Such a potent antioxidant effect of beta-carotene as observed in RBC was not confirmed in the plasma, liver or lungs, although their beta-carotene contents increased. The beta-carotene ingestion increased the all-trans-beta-carotene and retinol contents in RBC, plasma, liver and lungs, but the alpha-tocopherol content decreased. In the beta-carotene-supplemented (6 g and 30 g/kg diet) mice, cis-beta-carotene content was relatively higher in the RBC (25-35% of total beta-carotene) than that in the plasma, liver and lungs. The present findings indicate that not only does beta-carotene act as a potent antioxidant in vivo but also its antioxidant effect is very specific in the RBC phospholipid bilayers rather than in the plasma and other tissue organelles.

Cytoplasmic calcium level and membrane fluidity of platelets contacting poly(acrylamide-co-methacrylic acid) particles with different surface properties

Changes in cytoplasmic free calcium levels and membrane fluidity of platelets in contact with poly(acrylamide-co-methacrylic acid) (PAAmMAc) particles were examined to analyze the mechanistic aspect of regulating platelet function. Our previous studies demonstrated interesting features of PAAmMAc particles during interaction with platelets: (1) PAAmMAc particles induce no calcium increase but enhance membrane fluidity of platelets: (2) thrombin induces no calcium increase in platelets when the platelets were mixed previously with PAAmMAc particles; and (3) PAAmMAc particles induce a calcium increase in platelets when they were treated previously with sodium azide (NaN3). These results suggest the possibility that PAAmMAc surfaces may regulate the calcium level by influencing platelet metabolism. In this study, non-cross-linked PAAmMAc solution with the same chemical composition as the particles showed a suppressive effect on thrombin-induced calcium increase, but, no influence on membrane fluidity. This result indicates that aggregated macromolecular surface assemblies of PAAmMAc may dominate the increase in membrane fluidity of platelets although the calcium change is induced by discrete molecular level interaction between the PAAmMAc and platelet membranes. It was also revealed that the suppression of thrombin-induced calcium increase and the membrane fluidity increase in platelets by PAAmMAc particles were reduced by albumin-treatment of the particles. This result suggests that such phenomena may be due to a decrease in any physicochemical interaction of PAAmMAc surfaces with albumin, rather than platelet metabolic change. PAAmMAc particle surfaces with higher carboxyl groups exhibited a more suppressive effect on thrombin-induced calcium increase, whereas those with lower carboxyl groups derived a higher calcium increase when the platelets were treated previously with NaN3. These results suggest the importance of electrostatic and any other physicochemical interaction of PAAmMAc chains on regulating cytoplasmic calcium levels.