Ventricular-load optimization by inotropic stimulation in patients with heart failure

To evaluate the effects of inotropic stimulation on ventriculo-arterial coupling, we determined both the slope of the end-systolic pressure-volume relationship (ventricular elastance) and the slope of end-systolic pressure-stroke volume relationship (arterial elastance) at rest and during dobutamine infusion (5 micrograms/kg/min). We also determined stroke work, end-systolic potential energy and the ventricular work efficiency defined as stroke work per pressure volume area (stroke work + potential energy). In the resting state, ventricular elastance was lower than arterial elastance and work efficiency was about 59.7 +/- 9.3% (mean +/- SD). This condition is remote from the point where stroke work or mechanical efficiency is optimal. Enhanced ventricular elastance by 41% with dobutamine resulted in a significant reduction in both left ventricular end-diastolic and end-systolic volumes and was accompanied by the reduction in arterial elastance by 23%. Consequently, the ratio of arterial elastance to ventricular elastance decreased from 1.43 +/- 0.57 to 0.82 +/- 0.47, which resulted in an increase in stroke work, a decrease in potential energy and hence a marked increase in work efficiency. Thus, inotropic stimulation of depressed hearts could modulate ventriculo-arterial coupling towards optimization of either stroke work or mechanical efficiency.

Quantitative evaluation of blood flow distribution to exercising and resting skeletal muscles in patients with cardiac dysfunction using whole-body thallium-201 scintigraphy

BACKGROUND AND HYPOTHESIS

Decreased blood flow to working muscles makes an important contribution to exercise intolerance in patients with chronic heart failure. This study was undertaken to examine whether maldistribution of skeletal muscle blood flow is closely related to exercise intolerance in patients with cardiac dysfunction.

METHODS

Whole-body thallium scintigraphy was performed during one-leg exercise in 11 patients with left ventricular (LV) dysfunction (LV ejection fraction < 45%). Blood flow distribution to the exercising and resting legs was quantified by expressing regional thallium counts as a percentage of the whole-body counts at rest, at the level of anaerobic threshold, and at peak exercise.

RESULTS

At anaerobic threshold, the thallium activity of exercising muscle increased from 4.2 +/- 0.7 to 14.0 +/- 2.5% (p < 0.05) in the thigh and from 1.7 +/- 0.3 to 4.1 +/- 0.9% (p < 0.05) in the calf, compared with the resting value. Consequently, the ratio of thallium activity between exercising and resting legs increased to 2.7 +/- 0.7 (p < 0.05) in the thigh and to 2.3 +/- 0.7 (p < 0.05) in the calf. When plotted as a function of anaerobic threshold, thallium activity of the exercising thigh (r = 0.78, p < 0.05) and the thallium ratio between exercising and resting thigh (r = 0.69, p < 0.05) declined with the reduction of exercise tolerance. These correlations were not observed in calves.

CONCLUSION

Whole-body thallium scintigraphy demonstrated a maldistribution of leg blood flow in patients with reduced aerobic exercise capacity, suggesting that this abnormality could play an important role in exercising intolerance in these patients.

Immunoregulatory effects of transforming growth factor-beta in a prolonged period of culture

It is well known that transforming growth factor-beta (TGF-beta) strikingly inhibits numerous immune functions in short-term cultures. In this study we investigated the effects of TGF-beta on the immune responses of murine spleen cells in a prolonged period of culture. The addition of exogenous TGF-beta (0.1 ng/ml) inhibited the proliferation of Con A- or LPS-stimulated spleen cells, polyclonal IgM and IgG antibody production, and NK cell activity during 4 days of the initial culture and subsequently enhanced their responses on Day 10. The augmented polyclonal IgM and IgG responses in murine spleen cells induced by LPS and TGF-beta on Day 10 were suppressed by the secondary addition of TGF-beta on Day 6. These results suggest that TGF-beta acts as an immunoregulator in prolonged period responses by immunoactivators.

Central Sympathetic Inhibition Augments Sleep-Related Ultradian Rhythm of Parasympathetic Tone in Patients With Chronic Heart Failure

BACKGROUND

Abnormal sleep dynamics in patients with heart failure is one of the mechanisms for the relative predominance of central sympathetic outflow over parasympathetic tone. This study was designed to examine whether central sympathoinhibition could improve the sympathovagal imbalance related to rapid-eye-movement (REM)/non-REM ultradian sleep rhythm in these patients.

METHODS AND RESULTS

Beat-by-beat RR intervals of overnight electrocardiogram were serially subject to power spectral analysis in 14 patients with chronic heart failure and 13 age-matched subjects with normal cardiac function. To assess autonomic sleep dynamics, the ultradian rhythm was extracted from all-night consecutive high-frequency (HF) components of heart rate variability (HRV) before and after administration of an (alpha2)-adrenergic agonist, guanfacine. Night-time HRV in heart failure was characterized by an attenuated ultradian rhythm of HF-components with a concomitant reduction in averaged HF power. Guanfacine reduced blood pressure, heart rate, and plasma norepinephrine concentrations by 7%, 8%, and 34% (p < 0.01), respectively. After guanfacine, HF power rose by 154% (p < 0.01) with a prominent augmentation of the all-night ultradian rhythm (+361%, p < 0.01).

CONCLUSIONS

Central sympathoinhibition augments a sleep-related ultradian rhythm of parasympathetic tone, suggesting a potential benefit to autonomic balancing and sleep quality in patients with chronic heart failure.

Photodynamic inactivation of bladder cancer cells (MGH-U1) sensitized with acridine orange and irradiated by argon laser

Photodynamic inactivation of bladder cancer cells (MGH-U1) was investigated in order to apply laser therapy to the treatment of bladder cancer. After stained with acridine orange (AO), the material cells were irradiated with argon laser. After 24 hr incubation the survival was counted with a hemocytometer. The number of stained cells showed a less than 5% decrease and the number of irradiated (for 15 min) unstained cells showed no decrease compared with untreated cells. Participation of singlet oxygen process in inactivation of MGH-U1 cells was confirmed by the use of D2O and NaN3. The result shows that argon laser at the low intensity and with short irradiation time has a sufficient cytocydal effect, suggesting the usefulness of photodynamic inactivation of argon laser with topical use of acridine orange in the treatment of bladder cancer.

A possible immunomodulating activity of arbekacin (ABK), a newly synthesized antibiotic against methicillin-resistant Staphylococcus aureus (MRSA)

Arbekacin (ABK) is a newly developed aminoglycoside in Japan which can cause bactericidal effects on methicillin-resistant Staphylococcus aureus (MRSA). However, details of the mechanism on effective antibacterial activity of this drug in host patients has not been completely elucidated. We studied the modulating effects on some functional activities of immunocompetent cells in in vitro and in vivo mouse experimental systems. (i) ABK stimulated the phagocytic activity against S. aureus into mouse phagocytic cells in a dose-dependent manner. (ii) ABK enhanced oxygen radical generation with chemiluminescence in mouse phagocytic cells. (iii) ABK exhibited a stimulatory effect on interleukin 1 alpha release from mouse adherent cells. (iv) Injection with ABK into mice showed an adjuvant activity which stimulated antibody production against sheep red blood cells and S. aureus. These experimental results indicate the possibility that ABK has not only a direct antibacterial activity but also a modulating activity for immunocompetent cells to enhance host defense against S. aureus infection.

Augmentation of natural killer cell activity in mice by oral administration of transforming growth factor-beta

The latent form of transforming growth factor-beta (TGF-beta) in human milk and platelets was converted to the active form when conscious, pylorus-ligated mice were given human milk and platelets by intragastric intubation. Oral administration of TGF-beta exerted enhancing effects on the natural killer (NK)-cell activities in spleen and liver. Augmentation of NK-cell activities in spleen was observed for 7 days after oral administration of TGF-beta. TGF-beta at concentrations of 5 and 20 ng produced the greatest augmentation of NK-cell activities in spleen. However, NK-cell activities in spleen were unaffected when TGF-beta was given intravenously. Interleukin (IL)-12 production in spleen was enhanced by oral administration of TGF-beta, but not by intravenous administration of TGF-beta. These findings suggest that large amounts of TGF-beta in human milk are involved in early antiviral protection through the augmentation of NK-cell activities.

Effects of acetate on the immune system of mice

The effects of acetate on antibody production and cell-mediated immunity in mice were investigated. Polyclonal antibody responses could be enhanced in vivo by single intraperitoneal administration of acetate (5 mg/mouse) in C57BL/6 mice but not in DBA/2 mice. No enhancement of antibody production by acetate was also induced in athymic C57BL/6 nude mice and carrageenan-pretreated, macrophage-depleted mice. The inoculation of acetate-nonresponder BDF1 mice with T-cells and peritoneal adherent cells derived from acetate-treated C57BL/6 mice resulted in an enhanced antibody response. These results suggest that acetate increases polyclonal antibody responses in vivo by activating indirectly T-cells and macrophages. Acetate administration increased delayed hypersensitivity to pircryl chloride in C57BL/6 mice but not in DBA/2 mice. Allogeneic mixed lymphocyte reaction (MLR) of T-lymphocytes derived from the spleen of acetate-treated C57BL/6 mice was also enhanced. The natural killer (NK) activity and antibody-dependent cell-mediated cytotoxicity (ADCC) were also increased in C57BL/6 mice that were administered acetate. The possible mechanism of the immunopotentiating effect of this chemical is discussed.

Polyclonal antibody production induced by parotid protein and its active glycopeptide in mouse and human lymphocytes

Parotid protein (extracted from bovine parotid gland), one parotid subunit, and the active fragment (FrAA-1) induced polyclonal IgM, IgG, and IgA antibody production in murine spleen cells in vivo and in vitro. The parotid subunit also elicited polyclonal IgM antibody responses in immune defective CBA/N and LPS nonresponder C3H/HeJ mouse. When one carbohydrate residue in the subunit was removed by treatment with mixed galactosidase, the ability to generate nonspecific responses was markedly reduced. In human peripheral lymphocytes, the parotid subunit and FrAA-1 induced considerable polyclonal IgM antibody production. The subunit was not toxic to human lymphocytes. Therefore, it seems possible that parotid protein could be applied to immunopharmacological therapy for conditions such as immunodeficiency.

Immunopharmacological study of CCA (Lobenzarit disodium), an anti-arthritis agent--I. Abrogation of IL 1 secretion by LPS-stimulated human monocytes and induction of gamma-interferon production with CCA

In vitro effects of CCA, an anti-arthritis agent, were studied upon autologous mixed lymphocyte reaction (AMLR), lymphocyte mitogenesis, IL 1 and IL 2 production, immunoglobulin production and gamma-interferon (IFN) production. CCA at 50 micrograms/ml, which was not toxic to cells, blocked AMLR, IL 1 production and immunoglobulin production (IgM and IgG) significantly, while CCA at the same dose did not affect IL 2 production and lymphocyte mitogenic responses to Staphylococcus aureus Cowan I(SAC) and pokeweed mitogen(PWM). CCA at both 20 ng/ml and 20 micrograms/ml induced human gamma/IFN. Addition of IL 1 and/or IL 2 reversed inhibitory effect of CCA on AMLR. These data suggest that CCA exerts its actions by mainly affecting T cells and monocytes and can be used as an immunomodulator.

Implantation of xenografts into parkinsonian rat brain after portal venous administration of xenogeneic donor spleen cells

Object. The purpose of the present study was to examine the effect of pretransplantation portal venous immunization with ultraviolet B (UVB)—treated donor spleen cells on neural xenograft transplantation.

Methods. Cells from a murine catecholaminergic cell line derived from the B6/D2 F1 mouse, CATH.a, were used as a xenograft. Thirty hemiparkinsonian rats were divided into three different treatment groups. Group 1 received saline in the dopamine-denervated striatum; Group 2 received xenograft cells; and Group 3 received portal venous administration of UVB-irradiated B6/D2 F1 splenocytes 7 days before receiving xenograft cells. Xenograft function was determined by reviewing apomorphine-induced rotation at 2-week intervals, and xenograft survival was examined at 4 and 12 weeks after transplantation by immunohistochemical staining for murine tyrosine hydroxylase (THase). Rotational behavior was improved in both xenograft-transplanted groups (Groups 2 and 3); however, the animals in Group 3 displayed a significantly reduced rotational behavior compared with Group 2. In Group 2, many inflammatory cells and a few THase-positive cells were found at the graft sites 4 weeks after transplantation. In Group 3, however, a large number of THase-positive cells were found with few inflammatory cells. The THase-positive cells disappeared in the Group 2 rats at 12 weeks, but remained in Group 3 animals. In Group 3 rats proliferation of spleen cells in a mixed lymphocyte reaction was suppressed in a donor-specific fashion.

Conclusions. This work demonstrates improved neural xenograft survival and function by pretransplantation portal venous immunization with UVB-irradiated xenogeneic donor splenocytes. On the basis of these findings, the authors suggest the possibility of creating donor-specific immunological tolerance in the brain by administration of xenogeneic donor lymphocytes via the portal vein.

Adsorption of vitronectin in human serum onto plastics is augmented by sodium dodecyl sulfate

We have investigated the adsorption of cell-spreading activity in human serum onto polystyrene plates after treatment of the serum with sodium dodecyl sulfate (SDS). Vitronectin in human serum was remarkably adsorbed onto the plate after boiling the serum with 0.1% SDS for 5 min. SDS was effective over the concentration range from 0.05 to 0.25%. Increase of the vitronectin adsorption was accompanied by an increase of cell spreading on the plates. The cell-spreading activity in SDS-treated serum was impeded by anti-vitronectin antibody but not by anti-fibronectin antibody. After treatment with SDS, fibronectin-depleted serum could induce cell spreading but vitronectin-depleted serum could not. These results indicate that vitronectin alone was the cell-spreading factor in SDS-treated human serum. However, SDS-treated pure vitronectin itself did not retain the cell-spreading activity. The activity was recovered when bovine serum albumin was added to pure vitronectin before or after boiling with 0.1% SDS. Therefore, vitronectin adsorbed from SDS-treated serum might retain the cell-spreading activity with the aid of serum protein. Treatment of serum with SDS provides an easy, specific, and efficient method of coating polystyrene plates with vitronectin.

The degree of monocyte participation in human B- and T-cell activation by phorbol myristate acetate

The DNA synthetic responses of mononuclear cells (MNC), highly purified B and T lymphocytes, and T-cell subsets--OKT4+ and OKT8+ cells--and immunoglobulin production by a tumor-promoting agent, phorbol myristate acetate (PMA), were investigated. The following results were obtained: (1) PMA induced a significant DNA synthesis in MNC, pure B cells, pure T cells, and OKT4+ and OKT8+ cells. (2) Addition of monocytes to B cells did not increase the mitogenic responses more significantly than that of pure B cells alone. (3) PMA induced DNA synthesis in purified T cells significantly, but the addition of monocytes to the T cells augmented the responses markedly. (4) PMA induced polyclonal IgM production but the level of IgM synthesis was lower than that induced by PWM (about 45% at Day 6 culture). (5) Cyclosporin A (CyA) inhibited DNA synthesis induced by Con A and PHA, but did not inhibit the PMA-induced DNA synthesis. It was concluded that although there is a possibility that monocytes are not depleted completely, PMA did not seem to require monocytes for B-cell activation, whereas the level of T-cell activation was potentiated by monocyte addition and PMA probably activated T cells via receptors that are different from those used by Con A and PHA or probably activated T cells without HLA-DR antigen receptors.

IL-10 production in mouse hepatocytes augmented by TGF-beta

The supernatant from normal liver cell (Clone 1469) culture enhanced polyclonal antibody production in mouse spleen cells but not in human peripheral blood lymphocytes. The supernatants from transforming growth factor beta (TGF-beta)-treated C3H/HeN spleen cells augmented greatly polyclonal antibody responses compared with the untreated supernatants. IL-10 production and expression of mRNA for IL-10 in Clone 1469 cells was detected by using enzyme-linked immunosorbent assay, ELISPOT assay and PCR amplification. TGF-beta led to augmentation of IL-10 secretion from Clone 1469 cells.

Reparability of lethal lesions produced by phosphorus photoabsorption in yeast cells

The characteristics of DNA lesions produced by the photoabsorption of phosphorus in yeast cells were studied using monochromatized soft X-rays tuned to the absorption peak of the phosphorus K-edge (2153 eV) and below the peak energy (2147 eV). The repaired fractions of DNA double-strand breaks (dsb) were measured relatively by using both a mutant, rad 54-3, which shows the temperature-sensitive dsb repair-deficient phenotype, and a wild-type strain. The repaired fraction of lesion in rad 54-3, which corresponds to the relative yield of dsb reparable by the RAD 54 pathway, was not affected by the phosphorus photoabsorption. Repair of the produced lesions in the wild-type cells was also measured by comparing the surviving fraction of the immediately plated cells to that of those cells plated after holding in a non-nutrient medium for 80 hrs. The recovery of the surviving fraction after the holding treatment was dependent upon the irradiated X-ray energy. These results suggest that irreparable lesions are produced by the inner-shell photoabsorption of phosphorus in DNA, although its yield is small.

Neural modulation of ventriculoarterial coupling in conscious dogs

To investigate the role of autonomic reflexes in stroke-work optimization, we studied ventriculoarterial coupling in unanesthetized dogs with the autonomic system intact and blocked. Ventricular contractility was quantified by the slope of the end-systolic pressure-volume relation, ventricular elastance (Ees). Arterial system properties were quantified by the ratio of end-systolic pressure to stroke volume, arterial elastance (Ea). The coupling between left ventricle and arterial system was expressed by the Ea-to-Ees ratio. Changes in arterial blood pressure during nitroprusside or angiotensin II infusion were used to elicit reflex-mediated influences on ventriculoarterial coupling. With the autonomic system intact, Ees doubled during nitroprusside infusion while Ea remained unchanged due to reactive vasoconstrictor forces and tachycardia. Consequently, the Ea-to-Ees ratio fell 50% from baseline. Angiotensin II infusion increased Ea 46% but did not significantly change Ees, resulting in a 26% increase in the Ea-to-Ees ratio. In contrast to ventriculoarterial coupling, stroke work was insensitive to changes in afterload, remaining close to its theoretical maximum. After autonomic blockade, Ees tended to decrease during nitroprusside and increased during angiotensin II infusion in parallel with changes in Ea, so that the Ea-to-Ees ratio did not change from baseline as much as it did with the autonomic system intact. Again, the left ventricle maintained nearly 90% of its maximal stroke work. Thus, over a wide range of afterload, stroke work was kept near its theoretical maximum, independent of autonomic neural regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

B cell activating properties of parotid protein

A new biological activity of bovine parotid protein acting on immuno-competent lymphocytes to lead to polyclonal antibody responses was demonstrated. A significant amount of antibody to SRBC or antihapten antibody to TNP-SRBC, BPO-SRBC, or SA-SRBC was produced in mice by adding the appropriate doses of bovine parotid protein, suggesting that this protein may be a nonspecific B cell activator which acts on the B cells in a similar way as casein or gelatin.

Fosfomycin, an antibiotic, possessed TGF-beta-like immunoregulatory activities

The regulatory effects of fosfomycin (FOM) were correlated closely with the multifunction of TGF-beta in the modulation of immune responses in vivo and in vitro. LPS-induced polyclonal IgM and IgG antibody responses were depressed at 3 days after the initial culture and subsequently enhanced at day 10 by FOM or TGF-beta. Neither FOM nor TGF-beta inhibited LPS-induced IgA antibody responses, whereas dexamethasone (DX) reduced polyclonal IgM, IgG and IgA antibody responses wholly. The suppression of antibody responses and Mv1Lu cell proliferation induced by FOM or TGF-beta was partly overcome with soluble TFG-beta receptors (sRIII). Oral, i.v. and i.p. administration of FOM exhibited similar enhanced SRBC-specific antibody responses to that seen after oral administration of TGF-beta. The addition of FOM and latent TGF-beta inhibited the proliferation of Mv1Lu cells, but FOM did not lead to an increase in plasmin activities, which convert latent to active TGF-beta, and further the expression of TGF-beta receptors on the cell surface. In addition, FOM failed to enhance TGF-beta secretion. These findings suggest that immunomodulation of FOM results in increased sensitivity of cells to TGF-beta.

Defect in generation of LAK cell activity under oxygen-limited conditions

In general, the in vitro induction of lymphokine activated killer (LAK) cell activities by interleukin 2 (IL-2) in human peripheral blood mononuclear cells (PMNC) has been performed in an atmosphere of 5% CO2 in air (20% O2), whereas IL-2-induced LAK cell activities are considerably reduced under concentrations of 5% O2 equal to arterial blood oxygen tension (100 mmHg) and 2% O2 equal to venous blood oxygen tension (40 mmHg). Cultured cell viability, IL-2 receptor-beta expression on large granular lymphocytes (LGL), the percentage of IL-2 receptor-beta positive LGLs and cell proliferation were not affected by oxygen-limited conditions. LAK cells were induced by IL-2 over 5 days at 20% O2, at which time the LAK cells were further stimulated by IL-2 in 2% O2 and 20% O2. Under these conditions the activity of LAK cells in 2% O2 decreased day by day, while that of LAK cells induced in 20% O2 was maintained at least until day 10 of the original culture. LAK effector cell-mediated lysis was not influenced by oxygen-limited conditions. These results point to more successful applications of the combination of oxygen therapy and adoptive cellular immunotherapy in the clinic.

Linoleic acid salt with ultrapure soft water as an antibacterial combination against dermato-pathogenic Staphylococcus spp

AIMS

Skin colonization of Staphylococcus spp. critically affects the severity of dermatitis in humans and animals. We examined different types of fatty acid salts for their antibacterial activity against Staphylococcus spp. when used in ultrapure soft water (UPSW). We also evaluated their therapeutic effect on a spontaneous canine model of dermatitis.

METHODS AND RESULTS

UPSW, in which Ca(++) and Mg(++) were replaced with Na(+) , was generated using a water softener with cation-exchange resin. Staphylococcus aureus (Staph. aureus), Staphylococcus intermedius (Staph. intermedius), and Staphylococcus pseudintermedius (Staph. pseudintermedius) were incubated with various fatty acid salts in distilled water (DW) or UPSW and the number of bacteria was counted. Among the fatty acids, oleic acid salt and linoleic acid (LA) salt reduced the number of these bacteria. Also, UPSW enhanced the antibacterial effect of LA on Staph. spp. In spontaneously developed itchy dermatitis in companion dogs, shampoo treatment with liquid soap containing 10% LA in UPSW improved skin conditions.

CONCLUSIONS

LA salt showed antibacterial activity against Staph. spp. Treatment with soap containing LA with UPSW reduced clinical conditions in dogs with dermatitis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because colonization of Staph. spp. on the skin exacerbates dermatitis, the use of LA-containing soap in UPSW may reduce unpleasant clinical symptoms of the skin.

Segregation of modified bacteriorhodopsin aggregations in reconstituted vesicle membrane induced by the change of thermodynamical parameters

It was clearly shown that the change in thermodynamical parameters could cause the segregation of membrane protein aggregations in the phospholipid membrane. At first, reconstituted vesicles were prepared with a membrane protein, bacteriorhodopsin and a constituent phospholipid of biomembranes, L-alpha-dimyristoyl phosphatidylcholine. When the temperature of the suspension was decreased or the osmotic pressure was increased by adding poly(ethylene glycol) to this vesicle suspension at 23 degrees, the circular dichroism spectra showed a typical band indicating bacteriorhodopsin trimer formation implying their aggregation. This suggests that the aggregation of trimers proceeded by adding poly(ethylene glycol) into vesicle suspension, just as it proceeded by decreasing the temperature. Next, vesicles were prepared with fluorescein isothiocyanate-labeled bacteriorhodopsin, photoemissive bacteriorhodopsin and L-alpha-dimyristoyl phosphatidylcholine. The excitation energy transfer between the two modified proteins was measured by fluorescence spectroscopy. In this case, however, when poly(ethylene glycol) was added into the suspension, the yield of the excitation energy transfer decreased. This result indicates that modified proteins aggregate separately in a segregated form in the vesicle membrane.

Interaction between cell-binding domain and extracellular matrix-binding domain of fibronectin determined by fluorescence depolarization

Interaction of domains in fibronectin was observed by photometry of fluorescence polarization of three kinds of dye; [N-(1-anilinonaphthyl-4)]maleimide (ANM tau = 5 ns), [N-(3-fluoranthyl)]maleimide (FAM tau = 20 ns), and [N-(3-pyrene)]maleimide (PRM tau = 100 ns). Each dye was labeled at a free sulfhydryl group in the cell-binding domain. Neither fluorescence of ANM with short fluorescent lifetime, FAM with long lifetime, nor PRM with longer fluorescent lifetime on fibronectin depolarized as much as the free dye. It was found that each dye was firmly fixed in the cell-binding domain. When heparin or gelatin was added in the solution of PRM-fibronectin complex, the fluorescence polarization tended to increase principally by combining heparin or gelatin to fibronectin. It was found that the rotation of whole or partial fibronectin containing the cell-binding domain through fluorescent lifetime of 100 ns was suppressed by combining of heparin or gelatin to fibronectin. When heparin or gelatin was added in the solution of ANM- or FAM-fibronectin complex, on the contrary, the fluorescence polarization tended to decrease, that is, slightly depolarize through the fluorescent lifetime of 5 or 20 ns, respectively. It was found that the rotation of the cell-binding domain, or of part of the fibronectin molecule containing the domain, was slightly promoted by combining heparin or gelatin to its domain. These results indicate that an interaction of the heparin- or gelatin-binding domain with the cell-binding domain was induced by the combining of heparin or gelatin to the respective domains.

Intragastric administration of ursodeoxycholic acid suppresses immunoglobulin secretion by lymphocytes from liver, but not from peripheral blood, spleen or Peyer's patches in mice

Ursodeoxycholic acid (UDCA) has been recognized as a therapeutic drug for primary biliary cirrhosis (PBC) and chronic viral hepatitis. As one of the mechanisms by which UDCA improves liver function tests in those patients, its immunomodulatory effect is currently considered important. Although the suppressive effects of UDCA on some cytokine productions, T-cell mediated cytotoxicity and immunoglobulin production were observed from in vitro studies, the immunomodulation in vivo by UDCA remains unclear. In the present study, we investigated the effect of UDCA administration on the number of immunoglobulin secreting cells in liver, peripheral blood, spleen and Peyer's patches in mice using the enzyme linked immunospot assay and assessed whether the UDCA-mediated immunomodulation is liver-specific. It was demonstrated that intragastric administration of UDCA reduced immunoglobulin secretion by lymphocytes from liver, but not from peripheral blood, spleen, or Peyer's patches. However, immunoglobulin production of those lymphocytes cultured in the presence of UDCA was suppressed, irrespective of their distribution sites, in a UDCA dose-dependent manner. When the concentrations of UDCA in portal and peripheral blood were measured using high performance liquid chromatography, UDCA was detectable in the portal blood in UDCA-treated mice, but not in peripheral blood, suggesting that the concentrations of UDCA in the environment surrounding lymphocytes may be an important factor for the modulation of lymphocyte functions.