The T cell-directed CC chemokine TARC is a highly specific biological ligand for CC chemokine receptor 4

Thymus and activation-regulated chemokine (TARC) is a recently identified CC chemokine that is expressed constitutively in thymus and transiently in stimulated peripheral blood mononuclear cells. TARC functions as a selective chemoattractant for T cells that express a class of receptors binding TARC with high affinity and specificity. To identify the receptor for TARC, we produced TARC as a fusion protein with secreted alkaline phosphatase (SEAP) and used it for specific binding. By stably transfecting five orphan receptors and five known CC chemokine receptors (CCR1 to -5) into K562 cells, we found that TARC-SEAP bound selectively to cells expressing CCR4. TARC-SEAP also bound to K562 cells stably expressing CCR4 with a high affinity (Kd = 0.5 nM). Only TARC and not five other CC chemokines (MCP-1 (monocyte chemoattractant protein-1), RANTES (regulated upon activation, normal T cells expressed and secreted), MIP-1alpha (macrophage inflammatory protein-1alpha), MIP-1beta, and LARC (liver and activation-regulated chemokine)) competed with TARC-SEAP for binding to CCR4. TARC but not RANTES or MIP-1alpha induced migration and calcium mobilization in 293/EBNA-1 cells stably expressing CCR4. K562 cells stably expressing CCR4 also responded to TARC in a calcium mobilization assay. Northern blot analysis revealed that CCR4 mRNA was expressed strongly in human T cell lines and peripheral blood T cells but not in B cells, natural killer cells, monocytes, or granulocytes. Taken together, TARC is a specific functional ligand for CCR4, and CCR4 is the specific receptor for TARC selectively expressed on T cells.

Identification of CCR6, the specific receptor for a novel lymphocyte-directed CC chemokine LARC

Liver and activation-regulated chemokine (LARC) is a recently identified CC chemokine that is expressed mainly in the liver. LARC functions as a selective chemoattractant for lymphocytes that express a class of receptors specifically binding to LARC with high affinity. To identifiy the receptor for LARC, we examined LARC-induced calcium mobilization in cells stably expressing five CC chemokine receptors (CCR1-CCR5) and five orphan seven-transmembrane receptors. LARC specifically induced calcium flux in K562 cells as well as 293/EBNA-1 cells stably expressing an orphan receptor GPR-CY4. LARC induced migration in 293/EBNA-1 cells stably expressing GPR-CY4 with a bi-modal dose-response curve. LARC fused with secreted alkaline phosphatase (LARC-SEAP) bound specifically to Raji cells stably expressing GPR-CY4 with a Kd of 0.9 nM. Only LARC but not five other CC chemokines (MCP-1, RANTES, MIP-1alpha, MIP-1beta, and TARC) competed with LARC-SEAP for binding to GPR-CY4. By Northern blot analysis, GPR-CY4 mRNA was expressed mainly in spleen, lymph nodes, Appendix, and fetal liver among various human tissues. Among various leukocyte subsets, GPR-CY4 mRNA was detected in lymphocytes (CD4(+) and CD8(+) T cells and B cells) but not in natural killer cells, monocytes, or granulocytes. Expression of GPR-CY4 mRNA in CD4(+) and CD8(+) T cells was strongly up-regulated by IL-2. Taken together, GPR-CY4 is the specific receptor for LARC expressed selectively on lymphocytes, and LARC is a unique functional ligand for GPR-CY4. We propose GPR-CY4 to be designated as CCR6.

Effects of hydroxypropyl methylcellulose and other gelling agents on the handling properties of calcium phosphate cement

The calcium phosphate cement (CPC) used in this study was formed by combining equimolar amounts of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA). This powder, when mixed with water, sets to a hard cement in about 30 min. However, the water-based CPC paste is not highly cohesive and is vulnerable to washout until hardening occurs. The objectives of this study were to investigate the effects on handling properties, washout resistance, cement hardening behavior, and mechanical properties of adding several gelling agents to CPC paste. Aqueous solutions that contained a mass fraction of 2-4% of hydroxypropyl methylcellulose (HPMC), carboxyl methylcellulose (CMC), chitosan acetate, and chitosan lactate were used as cement liquids. Hardening time was measured by the Gilmore needle test; resistance to washout was evaluated by the disintegration of the cement specimen in water with agitation; and mechanical strength was evaluated by the measurement of diametral tensile strength and compressive strength. Handling properties were greatly improved by the addition of HPMC, CMC, chitosan acetate, and chitosan lactate. Hardening time was retarded by the additions of HPMC and CMC, and mechanical strength was weakened by the addition of either the chitosan lactate or the chitosan acetate.

Effect of angiotensin II on arteriovenous shunting assessed by hepatic arterial perfusion scintigraphy

Angiotensin II (AT II) has been reported to improve drug delivery in intraarterial chemotherapy for hepatic tumors. We studied the effect of this agent on arteriovenous (AV) shunting in the liver. Eleven patients with hepatic tumors and an indwelling catheter in the hepatic artery underwent hepatic arterial perfusion scintigraphy with and without AT II infusion. At baseline, following the administration of technetium-99m macroaggregated albumin (Tc-99m MAA) through the catheter, static images of the upper abdomen and whole-body anterior and posterior images were obtained. Two to 14 days later, AT II was infused via the catheter one minute prior to Tc-99m MAA injection, and imaging was performed in the same way as the baseline study. Visual interpretation of the static images showed improvement of drug delivery to the hepatic tumors in eight of 11 patients and no changes in the remaining patients. The percent injected dose in the lungs assessed quantitatively using the whole-body images increased in all patients, suggesting enhancement of AV shunt flow. It was concluded that intraarterial infusion of AT II increases AV shunting in the liver with better targeting to hepatic tumors.

Effects of tilisolol, a nonselective beta-adrenergic blocker, on the membrane currents of isolated guinea pig ventricular myocytes

The effects of tilisolol, a nonselective beta-adrenoceptor blocker, on transmembrane ionic currents were studied in single guinea pig ventricular myocytes by using the whole-cell voltage clamp technique. In the absence of beta-adrenergic stimulation, 10 microM tilisolol, a concentration higher than that used in the clinical therapeutic regimen, did not affect the L-type Ca2+ current (ICa), the inwardly rectifying K+ current (IK1), or the delayed rectifying K+ current (IK). In addition, it did not induce currents through the adenosine triphosphate (ATP)-sensitive K+ channels. However, under the nonselective beta-adrenergic stimulation with 1 microM isoproterenol, 1 microM tilisolol almost completely reversed the agonist-induced increase of IK. The increase of ICa by isoproterenol was blocked only by approximately 30% with tilisolol. We concluded that, at therapeutic concentrations (0.01-0.15 microM), tilisolol is a pure beta-adrenoceptor antagonist that has no direct effects on the transmembrane ionic currents of mammalian ventricular myocytes, such as ICa, IK1, or IK. Comparison of the dose-dependent effects of tilisolol on ICa and IK suggested that tilisolol may selectively inhibit catecholamine-induced increase of IK at the therapeutic concentrations. The virtually selective inhibition of IK, leaving ICa intact, may be favorable to prevent the catecholamine-induced arrhythmia without inhibiting contraction.

A comparative study of high-fat diet containing fish oil or lard on blood glucose in genetically diabetic (db/db) mice

The effects of high-fat diets containing fish oil or lard on blood glucose and plasma insulin after oral glucose loading were compared in genetically diabetic (db/db) mice, one of the animal models of non-insulin-dependent diabetes mellitus (NIDDM) with hyperinsulinemia. The blood glucose levels were significantly decreased in 27% of the mice fed high-fat diets containing 20% fish oil 30 and 60 min after the oral administration of glucose (both; p < 0.05). Conversely, the plasma insulin levels were significantly increased 30 min after the glucose loading as compared to 27% of the mice fed high-fat diets containing 20% lard (p < 0.01). In addition, a significant hypoglycemic effect was observed 60 min after the subcutaneous administration of insulin to mice on the fish oil diet (p < 0.05), whereas no effect was demonstrated in the case of those on the lard diet. The average body weight of the fish oil-treated mice was not significantly different from that of the lard-treated mice. The fish oil diet has a beneficial effect on glucose tolerance by increasing the insulin secretory capacity from pancreatic beta cells and also ameliorating insulin resistance.

Extracellular components implicated in the stationary organization of the actin cytoskeleton in mesophyll cells of Vallisneria

In mesophyll cells of Vallisneria gigantea Graebner, an aquatic angiosperm, the association of the plasma membrane with the cell wall at the end wall has been reported to be indispensable for the mechanism that maintains the stationary organization of the bundles of microfilaments (MFs) [Masuda et al. (1991) Protoplasma 162: 151]. To identify putative extracellular components that might play a crucial role in this mechanism, we examined the effects of two exogenously applied synthetic hexapeptides, GRGDSP and ARYDEI, which include an RGD and an RYD motif, respectively. The RGD motif is known as a recognition site in molecules required for adhesion to the substratum at sites of focal contacts. Within 24 h, both peptides (at concentrations of 1-15 mM) induced extremely abnormal patterns of cytoplasmic streaming, as well as the striking disruption of the arrangement of bundles of MFs. GRGESP and ARYEEI peptides, used as controls, had no detectable effects. Immunofluorescence microscopy revealed that polyclonal antibodies against the ARYDEI peptide bound to the cell walls of mesophyll cells while a preimmune serum did not. Western blotting analysis demonstrated that the antibodies recognized polypeptides of 54 kDa and 27 kDa in an extract of total proteins from the leaves of Vallisneria. The results suggest that some extracellular proteins(s), with a conserved RGD or RYD motif in its amino acid sequence, might be involved in the maintenance of the stationary organization of the bundles of MFs.

[Pupillary abnormalities in a patient with clinically diagnosed corticobasal degeneration]

We report a 65-year-old woman, who suffered from clumsiness of the left hand for 6 years. Gait disturbance, body balance impairment and rigidity of the left arm appeared progressively. Anti-parkinsonian drugs such as 1-dopa, doroxidopa, amantadine and bromocriptine were ineffective. Magnetic resonance imaging showed brain atrophy, especially in the right fronto-parietal lobes. Positron emission tomography (18F-fluoro-2-deoxy-D-glucose) showed decreased glucose metabolism in the right cerebral cortex, putamen and thalamus. A diagnosis of corticobasal degeneration was made, based on the clinical manifestations, MRI and PET findings. She also showed anisocoria, vertical gaze palsy and abnormal pupillary reactions. Her left pupil showed an oval figure shifted from the center position. The pupils exhibited denervation supersensitivity in the 0.125% pilocarpine test. We consider that her pupillary abnormalities may be related to her midbrain lesion (midbrain corectopia) associated with corticobasal degeneration.

Effect of a two-solution fluoride mouth rinse on deposition of loosely bound fluoride on sound root tissue and remineralization of root lesions in vitro

A constant-composition fluoride (F) titration method was used to measure the amount of leachable F deposited on root surfaces in vitro by a 1-min rinse with a 12 mmol/l sodium fluoride (228 micrograms/g F) solution or a two-solution rinse that contained 2 mmol/l sodium fluorosilicate (228 micrograms/g total F ) and 10 mmol/l calcium chloride. The mean +/- standard deviations (n = 3) F uptake from the two rinse treatments were 0.70 +/- 0.24 micrograms/cm2 and 3.25 +/- 0.74 micrograms/cm2, respectively. In a separate experiment, the effects of sodium fluoride and the two-solution rinses on remineralization of root lesions were evaluated in an in vitro pH cycling model. The results showed that the average decrease in mineral loss (delta Z) in the two-solution rinse group (60%) was significantly greater than that obtained in the NaF rinse (41%) or the control (9%) group.

Characteristics of laryngeal receptors analyzed by presynaptic recording from the cat medulla oblongata

In order to clarify the neural mechanisms for the protective laryngeal reflex, we conducted physiological analysis of laryngeal sensory receptors. In the present study, presynaptic unit activities, which might accurately reflect characteristics of the laryngeal receptor, were recorded with a glass microelectrode in the nucleus of the tractus solitarius of the medulla oblongata in ketamine-urethane anesthetized cats, and the responses to the mechanical and/or chemical stimuli were analyzed. From the results, it was demonstrated that highly sensitive mechanoreceptors and polymodal receptors exist in the laryngeal mucosa; they are particularly numerous in the laryngeal surface of the epiglottis and arytenoid region, and uncommon in the vocal fold. Mechanoreceptors on the laryngeal mucosa were classified into a rapidly adapting group and a slowly adapting group, while all polymodal receptors adapted rapidly to mechanical stimulation. These results suggest that these non-specific polymodal and rapidly adapting receptors may correspond to more superficial receptors such as free nerve endings and some taste buds, and also monomodal slowly adapting mechanoreceptors may correspond to deeper terminals in the subepithelium. It is also considered possible that the structures and the characteristics of these receptors are appropriate to elicit the protective laryngeal reflexes by non-specifically detecting various kinds of stimuli.

Clinical and prognostic significance of femoral marrow magnetic resonance imaging in patients with malignant lymphoma

We evaluated 56 consecutive patients with newly diagnosed lymphoma including 48 with non-Hodgkin's lymphoma (NHL) and 8 with Hodgkin's disease to determine the clinical and prognostic significance of magnetic resonance imaging (MRI) of the femoral marrow. MR images of the femoral marrow were obtained by the T1-weighted spin echo method and the short TI inversion recovery technique. Abnormal "positive" images were seen in 29 of the 56 patients (52%). All 17 patients with positive biopsy results showed abnormal images on their femoral marrow MRI. Three "positive" MRI patterns-scattered (72%), uniform (21%), and nodular (7%)-were observed. The overall survival of the patients with a positive MRI pattern was significantly poorer than that of patients with a normal pattern (P = .0129). Survival did not differ significantly according to MRI pattern. The 3-year survival rate in the patients with a normal MRI pattern was 89.9% and in the patients with a positive MRI pattern, it was 41.0%. This difference was statistically significant (P = .0279) when we evaluated only the patients with NHL. Patients with positive MRI patterns, but a normal bone marrow histology, showed a significantly shorter survival than those with a normal MRI pattern (P = .016). These results indicate that abnormal MR images of the femoral marrow are associated with a significantly poorer survival in patients with malignant lymphoma, regardless of histologic findings in the marrow.

Differential transactivation of the intercellular adhesion molecule 1 gene promoter by Tax1 and Tax2 of human T-cell leukemia viruses

Previously, we showed that surface expression of intercellular adhesion molecule 1 (ICAM-1) was strongly upregulated in T cells carrying proviral human T-cell leukemia virus type 1 (HTLV-1) and that the viral transactivator protein Tax1 was capable of inducing the ICAM-1 gene. To determine the responsive elements in the human ICAM-1 gene promoter, a reporter construct in which the 5'-flanking 4.4-kb region of the ICAM-1 gene was linked to the promoterless chloramphenicol acetyltransferase (CAT) gene was cotransfected with expression vectors for Tax1 and Tax2, both of which were separately confirmed to be potent transactivators of the HTLV-1 long terminal repeat (LTR). Tax1 strongly activated the ICAM-1 promoter in all the cell lines tested: three T-cell lines (Jurkat, MOLT-4, and CEM), one monocytoid cell line (U937), and HeLa. Unexpectedly, Tax2 activated the ICAM-1 promoter only in HeLa. By deletion and mutation analyses of the 1.3-kb 5'-flanking region, we found that Tax1 transactivated the ICAM-1 promoter mainly via a cyclic AMP-responsive element (CRE)-like site at -630 to -624 in the Jurkat T-cell line and via an NF-kappaB site at -185 to -177 and an SP-1 site at -59 to -54 in HeLa. On the other hand, Tax2 was totally inactive on the ICAM-1 promoter in Jurkat but transactivated the promoter via the NF-kappaB site at -185 to -177 in HeLa. Gel mobility shift assays demonstrated proteins specifically binding to the CRE-like site at -630 to -624 in Tax1-expressing T-cell lines. Stable expression of Tax1 but not Tax2 in Jurkat subclones enhanced the surface expression of ICAM-1. The differential ability of Tax1 and Tax2 in transactivation of the ICAM-1 gene may be related to the differential pathogenicity of HTLV-1 and HTLV-2.

Anti-cancer agent OK432 induces manganese superoxide dismutase in human granulocytes

Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme involved in scavenging O2-. OK432, a Streptococcal preparation, has anti-tumor activity and is also known to be a biological-response modifier. In this study, we have examined the regulation of MnSOD gene by OK432 in human granulocytes. Granulocytes had a low activity of MnSOD; OK432 increased MnSOD mRNA levels in a dose-dependent manner and its activity in granulocytes. OK432 also induced the MnSOD mRNA in HL60 promyelocytes, while not affecting the levels of MnSOD mRNA in human fibroblasts. Pre-treatment with either actinomycin D or cycloheximide inhibited the induction of MnSOD mRNA by OK432. OK432 increased the levels of interleukin-1 (IL-1) and tumor-necrosis-factor-alpha (TNFalpha) mRNA in granulocytes. Furthermore, the induction of MnSOD mRNA by OK432 was blocked by anti-IL-1 antibody but not by anti-TNF antibody. These results suggest that the induction of MnSOD mRNA by OK432 is regulated at the transcriptional level, and OK432 induces MnSOD mRNA, at least in part, through production of IL-1 in granulocytes.

The role of magnetic resonance imaging in the diagnosis and monitoring of myelodysplastic syndromes or leukemia

Magnetic resonance imaging (MRI) can provide valuable information about regions of the bone marrow which are inaccessible to biopsy. MRI also is unique in characterizing normal and abnormal bone marrow because of its ability to distinguish fat from other tissues. In patients with myelodysplastic syndromes (MDS) or leukemia, marrow MRI is an important tool for accurate diagnosis and monitoring and may function as an adjunct to bone marrow aspiration and biopsy. In clinical practice, defining the anatomic distribution and extent of marrow involvement by MRI is of advantage in the management of patients with MDS or leukemia.

Establishment of gastric Helicobacter pylori infection in Mongolian gerbils

An animal model of Helicobacter pylori infection was obtained with Mongolian gerbils. Culture broth of H. pylori ATCC 43504 was orally administered to the gerbils. Animals were killed 1, 7, 14, 21, and 42 days after the oral inoculation and the stomachs were excised. Colonization of H. pylori was maintained in the stomachs of all animals throughout the study period of up to 42 days. On microscopic examination after immunological and hematoxylin and eosin staining, the organisms were detected in the mucus layer of the gastric epithelium. All gerbils exhibited a slowly progressive but typical gastritis, showing superficial erosion with increasing numbers of infiltrating neutrophils and mononuclear cells. Forty-two days after the inoculation, lymph follicles were detected in the gastric submucosa. These features are similar to the manifestations of H. pylori infection in humans and, accordingly, this model could be of value for studying H. pylori pathogenicity and for research into agents for the treatment of H. pylori infection in humans.

[MR imaging of the femoral marrow in adult acute leukemia: correlation of MRI patterns with FAB subtype and prognosis]

MR imaging of the femoral marrow was performed in 36 patients with untreated acute myeloid leukemia (AML) and 7 patients with acute lymphocytic leukemia (ALL). The MRI appearance was classified into five patterns: 1) fatty marrow; 2) faint signal; 3) nodular pattern; 4) heterogeneous infiltration; and 5) diffuse infiltration. The MRI patterns of the femoral marrow were compared among the FAB subtypes of acute leukemia, and the MRI patterns were correlated with prognosis. All five MRI patterns were observed in the femoral marrow in adult acute leukemia, and diffuse infiltration was most commonly seen (41.9%). A completely fatty marrow was also depicted in two cases (4.7%) and faint signal in four cases (9.3%) in spite of untreated acute leukemia. The M2 subtype of AML tended to be demonstrated as a minimally abnormal MRI finding, which was significantly different from the other types of AML. The patients who showed fatty marrow or faint signal were thought to have a good prognosis, while diffuse or heterogeneous infiltration was regarded as a poor prognostic sign. However, there were some exceptions to these rules, and no significant differences were revealed in prognosis between minimally abnormal and advanced MRI patterns. We concluded that MRI of the femoral marrow could be useful in the assessment of tumor volume of adult acute leukemia, and that there were limitations to predicting prognosis on the basis of the MRI manifestations.