A case of life-threatening refractory polychondritis successfully treated with combined intensive immunosuppressive therapy with methotrexate

Relapsing polychondritis (RP) is a rare disease of unknown etiology causing systematic inflammation and resulting in destruction of cartilaginous tissues. We describe here an 18-year-old Japanese woman who developed severe airway stenosis as the initial symptom with auricular, nasal, and ocular inflammation. The effect of high dose oral steroid, methylprednisolone pulse therapy, and cyclophosphamide was temporary and her conditioning was worsening. Finally we added methotrexate to the immunosuppressive treatment and achieved reduction of disease activity. This case illustrates the potentially fatal sudden onset of airway inflammation that can occur with this disorder, and the effectiveness of methotrexate.

Cytohesin binder and regulator (cybr) is not essential for T- and dendritic-cell activation and differentiation

Cybr (also known as Cytip, CASP, and PSCDBP) is an interleukin-12-induced gene expressed exclusively in hematopoietic cells and tissues that associates with Arf guanine nucleotide exchange factors known as cytohesins. Cybr levels are dynamically regulated during T-cell development in the thymus and upon activation of peripheral T cells. In addition, Cybr is induced in activated dendritic cells and has been reported to regulate dendritic cell (DC)-T-cell adhesion. Here we report the generation and characterization of Cybr-deficient mice. Despite the selective expression in hematopoietic cells, there was no intrinsic defect in T- or B-cell development or function in Cybr-deficient mice. The adoptive transfer of Cybr-deficient DCs showed that they migrated efficiently and stimulated proliferation and cytokine production by T cells in vivo. However, competitive stem cell repopulation experiments showed a defect in the abilities of Cybr-deficient T cells to develop in the presence of wild-type precursors. These data suggest that Cybr is not absolutely required for hematopoietic cell development or function, but stem cells lacking Cybr are at a developmental disadvantage compared to wild-type cells. Collectively, these data demonstrate that despite its selective expression in hematopoietic cells, the role of Cybr is limited or largely redundant. Previous in vitro studies using overexpression or short interfering RNA inhibition of the levels of Cybr protein appear to have overestimated its immunological role.

Conceptual equivalence and health-related quality of life: an exploratory study in Japanese and Dutch cancer patients

Research into the equivalence of Western and Japanese conceptualizations of health-related quality of life (HR-QOL) is scarce. We used the Western (European Organization for Research and Treatment of Cancer, EORTC-QLQ-C30) and the Japanese (HRQoL-20) questionnaire in order to analyze the conceptual similarity of HR-QOL factors, and the associations between specific symptom items with overall HR-QOL in Japanese (n=265) and Dutch (n=174) patients with various types of cancer. Both populations completed both instruments. In both patient groups, the overall health scale of the EORTC-QLQ-C30 correlated highly (r=0.59; p<0.001) with the HRQOL-20 composite average score, indicating substantial conceptual comparability. Relationships between all EORTC-QLQ-C30 symptom items with HR-QOL were examined by ranking their correlations with the two overall measures of HR-QOL. Comparable patterns in the Japanese and Dutch samples were observed. The results suggest a considerable conceptual equivalence of HR-QOL in Japanese and Dutch cancer patients, and indicate a satisfactory structural and cross-cultural equivalence for the EORTC-QLQ-C30 with regard to items measuring functioning and specific symptoms. Longitudinal studies are needed to examine the impact of specific symptoms on general quality of life.

Na+ channel pharmacology and molecular mechanisms of gating

Electrogenesis of efficiently propagated action potentials requires synchronized opening of transmembrane Na+ channels possessing a sodium selectivity-filter, a high-throughput ion-conductance pathway, and voltage-dependent gating functions. These properties of the Na+ channel have long been the target of molecular analysis. Several toxins and drugs, known to selectively bind to Na+ channels, have been used as pharmacological tools to investigate Na+ channel properties either electrophysiologically or chemically. Recent analyses of the protein crystal structure of bacterial voltage-dependent K+ channels have provided important clues to the identity of mobile structures involved in channel gating. The new information may be applicable to Na+ channels, and may well require a total revision of our understanding of gating mechanisms of sodium channels. Several experiments challenge the emerging view that channel gating by S6 transmembrane segments is triggered by signals from voltage sensors floating in membrane lipid. Herein, we review the various toxin and drug molecules that affect the gating behavior of Na+ channels in this new structural framework, by characterizing the binding sites of these toxins, and assessing the pharmacological effects resulting from changes in the structure of the toxin or sodium channel.

Stat5a/b are essential for normal lymphoid development and differentiation

Cytokines that use the common gamma chain gammac are critical for lymphoid development and function. Mutations of the IL-7 receptor, gammac, or its associated kinase, Jak3, are the major cause of human severe combined immunodeficiency. Although activated by IL-7, Stat5a/b (Stat, signal transducer and activator of transcription) have been thought to play limited roles in lymphoid development. However, we now show that mice completely deficient in Stat5a/b have severely impaired lymphoid development and differentiation. Absence of Stat5 also abrogates T cell receptor gamma rearrangement and survival of peripheral CD8(+) T cells. Thus, deficiency of Stat5 results in severe combined immunodeficiency, similar in many respects to deficiency of IL-7R, gammac, and Jak3.

Pulmonary adenocarcinoma with micropapillary component: an immunohistochemical study. Case report

Micropapillary carcinoma has been described in various organs, including the breast, urinary bladder, ovary and lung. We here present a case of pulmonary micropapillary carcinoma in a 72-year-old Japanese man who died of respiratory failure and septic shock, following which autopsy was performed. A mass measuring 2.5 x 2.5 x 2.5 cm was observed in the left lower lobe of the lung. The tumor showed moderately differentiated papillary adenocarcinoma with a focal micropapillary component. Carcinomatous lymphangiosis was also observed in the left lung and metastatic lesions were observed in the bilateral lung, liver, vertebra, muscle layer of the urinary bladder, right adrenal gland, spleen and lymph nodes. The micropapillary component was predominant at some metastatic sites. Immunohistochemically, both the adenocarcinoma and micropapillary components were positive for cytokeratin (CK) 7, CK19, TTF (thyroid transcription factor)-1, carcinoembryonic antigen (CEA) and surfactant apoprotein A (SP-A), and negative for CK20, estrogen receptor, progesterone receptor, uroplakin III, and CA125. The invasive area of the conventional adenocarcinoma component contained a large number of myofibroblasts, whereas the stroma of the micropapillary component contained a small number of myofibroblasts. However, no myofibroblasts were observed in the stroma of the central core of the non-invasive micropapillary carcinoma. Several lymphatic invasions by neoplastic cells were identified in the peripheral area of the micropapillary component using D2-40 antibody. The immunohistochemical profile may be helpful in determining the primary location of the neoplasm containing micropapillary features. Myofibroblasts are present in the stroma of the invasive neoplastic nests in the micropapillary component as well as the conventional adenocarcinoma component, and D2-40 monoclonal antibody may be useful for evaluating the lymphatic invasion of pulmonary micropapillary carcinoma.

Jak3 negatively regulates dendritic-cell cytokine production and survival

Cytokines are critical in regulating the development and function of diverse cells. Janus kinase 3 (Jak3) is a tyrosine kinase expressed in hematopoietic cells that associates with the common gamma chain (gammac) and is required for signaling for a family of cytokines including interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21; deficiency of either Jak3 or gammac results in severe combined immunodeficiency (SCID). While Jak3 is essential for lymphoid-cell development, the potential roles for Jak3 in regulating dendritic cells (DCs) were unclear. Herein, we show that although CD8+CD11c+ splenic DCs are absent in Jak3-/- mice, bone marrow-derived DCs developed normally in vitro from Jak3-/- precursor cells. In fact, the survival of Jak3-/- DCs was enhanced, and they expressed lower levels of proapoptotic proteins. Jak3-/- DCs exhibited normal antigen uptake and up-regulation of costimulatory molecules. However, Jak3-/- DCs produced more IL-12 and IL-10 in response to Toll-like receptor ligands, which correlated with enhanced T helper 1 (Th1) differentiation in vivo. In summary, Jak3 is not essential for DC development but unexpectedly appears to be an important negative regulator. These results may be relevant clinically for patients with SCID who have undergone hematopoietic stem cell transplantation and for patients who might be treated with a Jak3 inhibitor.

IFN regulatory factor-4 and -8 govern dendritic cell subset development and their functional diversity

Dendritic cells (DCs) are bone marrow (BM)-derived APCs central to both innate and adaptive immunity. DCs are a heterogeneous cell population composed of multiple subsets with diverse functions. The mechanism governing the generation of multiple DC subsets is, however, poorly understood. In this study we investigated the roles of closely related transcription factors, IFN regulatory factor (IRF)-4 and IRF-8, in DC development by analyzing IRF-4(-/-), IRF-8(-/-), and IRF-4(-/-)IRF-8(-/-) (double-knockout) mice. We found that IRF-4 is required for the generation of CD4(+) DCs, whereas IRF-8 is, as reported previously, essential for CD8alpha(+) DCs. Both IRFs support the development of CD4(-)CD8alpha(-) DCs. IRF-8 and, to a lesser degree, IRF-4 contribute to plasmacytoid DC (PDC) development. Thus, the two IRFs together regulate the development of all conventional DCs as well as PDCs. Consistent with these findings, IRF-4, but not IRF-8, was expressed in CD4(+) DCs, whereas only IRF-8 was expressed in CD8alpha(+) DCs. CD4(-)CD8alpha(-) DCs and PDCs expressed both IRFs. We also demonstrate in vitro that GM-CSF-mediated DC differentiation depends on IRF-4, whereas Fms-like tyrosine kinase 3 ligand-mediated differentiation depends mainly on IRF-8. Gene transfer experiments with double-knockout BM cells showed that both IRFs have an overlapping activity and stimulate a common process of DC development. Nonetheless, each IRF also possesses a distinct activity to stimulate subset-specific gene expression, leading to the generation of functionally divergent DCs. Together, IRF-4 and IRF-8 serve as a backbone of the molecular program regulating DC subset development and their functional diversity.

CXCL12 Signaling Is Independent of Jak2 and Jak3

Janus kinases (Jaks) are a small family of cytoplasmic tyrosine kinases, critical for signaling by Type I and II cytokine receptors. The importance of Jaks in signaling by these receptors has been firmly established by analysis of mutant cell lines, the generation of Jak knock-out mice, and the identification of patients with Jak3 mutations. While a number of other ligands that do not bind Type I and II cytokine receptors have also been reported to activate Jaks, the requirement for Jaks in signaling by these receptors is less clear. Chemokines for example, which bind seven transmembrane receptors, have been reported to activate Jaks, and principally through the use of pharmacological inhibitors, it has been argued that Jaks are essential for chemokine signaling. In the present study, we focused on CXCR4, which binds the chemokine CXCL12 or stromal cell-derived factor-1, a chemokine that has been reported to activate Jak2 and Jak3. We found that the lack of Jak3 had no effect on CXCL12 signaling or chemotaxis nor did overexpression of wild-type versions of the kinase. Similarly, overexpression of wild-type or catalytically inactive Jak2 or "knocking-down" Jak2 expression using siRNA also had no effect. We also found that in primary lymphocytes, CXCL12 did not induce appreciable phosphorylation of any of the Jaks compared with cytokines for which these kinases are required. Additionally, little or no Stat (signal transducer and activator of transcription) phosphorylation was detected. Thus, we conclude that in contrast to previous reports, Jaks, especially Jak3, are unlikely to play an essential role in chemokine signaling.

The Janus kinases (Jaks)

The Janus kinase (Jak) family is one of ten recognized families of non-receptor tyrosine kinases. Mammals have four members of this family, Jak1, Jak2, Jak3 and Tyrosine kinase 2 (Tyk2). Birds, fish and insects also have Jaks. Each protein has a kinase domain and a catalytically inactive pseudo-kinase domain, and they each bind cytokine receptors through amino-terminal FERM (Band-4.1, ezrin, radixin, moesin) domains. Upon binding of cytokines to their receptors, Jaks are activated and phosphorylate the receptors, creating docking sites for signaling molecules, especially members of the signal transducer and activator of transcription (Stat) family. Mutations of the Drosophila Jak (Hopscotch) have revealed developmental defects, and constitutive activation of Jaks in flies and humans is associated with leukemia-like syndromes. Through the generation of Jak-deficient cell lines and gene-targeted mice, the essential, nonredundant functions of Jaks in cytokine signaling have been established. Importantly, deficiency of Jak3 is the basis of human autosomal recessive severe combined immunodeficiency (SCID); accordingly, a selective Jak3 inhibitor has been developed, forming a new class of immunosuppressive drugs.

Molecular mechanisms of lipopolysaccharide-induced cyclooxygenase-2 expression in human neutrophils: involvement of the mitogen-activated protein kinase pathway and regulation by anti-inflammatory cytokines

Neutrophils are an important cellular source of proinflammatory mediators, whose regulation may be of potential benefit for the treatment of a number of inflammatory diseases. However, the mechanisms of lipopolysaccharide (LPS)-induced neutrophil activation and its regulation by anti-inflammatory cytokines have not yet been fully elucidated. Recent studies have revealed that mitogen-activated protein kinases (MAPK) play a crucial role in the generation of proinflammatory mediators in some cell types. Therefore, we conducted this study to determine whether MAPK activation could be involved in prostaglandin E(2) (PGE(2)) production and cyclooxygenase (COX)-2 expression in LPS-stimulated human neutrophils. PD98059 (MEK1 inhibitor) and SB203580 (p38(MAPK) inhibitor) reduced PGE(2) production as well as COX-2 expression in LPS-stimulated neutrophils. In addition, both extracellular signal-regulated protein kinase (ERK) and p38(MAPK) were phosphorylated and activated in time- and dose-dependent manners. Since we previously showed that IL-10 and IL-4 similarly inhibited COX-2 expression in LPS-stimulated neutrophils, we next tested the effects of IL-10 and IL-4 on the phosphorylation and activation of both kinases. IL-10 inhibited the phosphorylation and activation of p38(MAPK), but not ERK. In addition, IL-4 caused a marginal inhibition in the activation of p38(MAPK). Taken together, these results suggest that both ERK and p38(MAPK) pathways are involved in LPS-induced COX-2 expression and PGE(2) production in neutrophils, and IL-10 and IL-4 inhibit neutrophil prostanoid synthesis by down-regulating the activation of p38(MAPK).

Basic study on radon effects and thermal effects on humans in radon therapy

Because most of the diseases to which radon (222Rn) therapy is applied are related to activated oxygen, in this study the effect of the radioactivity of radon and the thermal effect were compared under a room or a hot spring condition with the same chemical component using as the parameters the activity of superoxide dismutase (SOD), which is an oxidation inhibitor, and lipid peroxide and low density lipoprotein (LDL)-cholesterol, which are closely involved in arteriosclerosis. Results show that the SOD activity was significantly increased, and the lipid peroxide and LDL-cholesterol levels were significantly decreased on days 6 and 7 of study. The results were about 2-fold larger in the radon group than in the thermo group. This suggests that the anti-oxidation function was more enhanced by radon therapy than by thermo therapy, and suggests that radon therapy may help to prevent the causes of life style-related diseases such as arteriosclerosis. These findings are important in understanding the mechanism of diseases in which radon therapy is used as treatment, and most of which are called activated oxygen-related diseases.

Novel mutations in the a3 subunit of vacuolar H(+)-adenosine triphosphatase in a Japanese patient with infantile malignant osteopetrosis

A case of infantile malignant osteopetrosis is described. The patient died from respiratory hemorrhage at 7 months of age despite treatment that included high doses of active vitamin D and administration of interferon-gamma. A postmortem examination revealed the presence of many osteoclasts in the bone, which lacked ruffled borders. This observation was consistent with the histology of bone reported in Atp6i-knockout mice, which lack the gene encoding the a3 subunit of vacuolar-type H(+)-adenosine triphosphatase (ATPase). Sequence analysis of the TCIRG1 gene encoding the a3 subunit revealed two novel mutations: a deletion/insertion mutation in exon 9 and a T-to-C transition at the splice donor site of intron 19. The former mutation caused a frame shift and premature stop codon. The latter was associated with abnormal splicing, which was confirmed by sequencing the products amplified by reverse transcription-polymerase chain reaction (RT-PCR), using total RNA from the liver specimen as template. Although several mutations in the TCIRG1 gene in infantile malignant osteopetrosis have been reported in other populations, this is the first case of a Japanese patient with a mutation identified in this gene. These results support the important role of the subunit in the function of the proton pump.

Open carpal tunnel decompression in long-term haemodialysis patients [corrected]

This retrospective study assessed the treatment of 91 cases of carpal tunnel syndrome in long-term haemodialysis patients. One group of patients underwent an enlargement reconstruction of the flexor retinaculum with synovectomy and the other group was treated with a conventional carpal tunnel release. There were no major changes or differences between the outcomes of the two groups. However, there was an earlier functional recovery of grip strength and a lower recurrence rate in the enlargement plasty with synovectomy group.

Introduction of recirculatory analysis into portal and systemic concentration difference method

Recirculatory analysis was introduced into the portal and systemic concentration difference method with double dosing (PS-DD method), which is an evaluation system for the local intestinal and hepatic first-pass effect. 5-Fluorouracil (5-FU) and cephalexin (CEX) were selected as model drugs. A new recirculatory system was constructed to predict the time courses of a drug concentration in the systemic and portal bloods. Bioavailability (F), local absorption ratio (Fa), hepatic recovery ratio (FH), and local mean absorption time (ta) estimated by recirculatory analysis were close to those calculated by moment analysis with numerical integration. Using recirculatory analysis, the sampling period was considerably shortened and the sampling number was also reduced, which demonstrates that recirculatory analysis is useful in PS-DD method.

Novel site on sodium channel alpha-subunit responsible for the differential sensitivity of grayanotoxin in skeletal and cardiac muscle

We searched for sites on the alpha-subunit of the fast Na(+) channel responsible for the difference in GTX (grayanotoxin) sensitivity of the skeletal- and cardiac-muscle Na(+) current. cDNA clones, encoding the skeletal or cardiac isoforms of the alpha-subunit, were inserted into a mammalian expression vector and transiently transfected into human embryonic kidney cells. The expressed channels were measured using whole-cell patch-clamp techniques and examined for GTX sensitivity. As a measure of GTX sensitivity, we used relative chord conductance (ratio of maximum chord conductance of noninactivating GTX-modified Na(+) currents to that of unmodified peak currents). Wild-type channels from skeletal muscle (mu 1) were more sensitive to GTX modification than wild-type cardiac channels (rH1) by a factor of 1.6. To facilitate exploration of alpha-subunit sites determining GTX sensitivity, we used SHHH, a chimera of skeletal muscle (S) domain D1 and heart muscle (H) domains D2D3D4 with supernormal sensitivity to GTX I (1.5-fold of wild-type mu 1). Successive replacement of Ser-251 (D1S4-S5 intracellular loop) and Ile-433 (D1S6 transmembrane segment), with corresponding rH1 residues Ala and Val, reduced, in a stepwise manner, the GTX sensitivity of the chimera and related mutants to that of wild-type rHl. We concluded that, in addition to Ile-433, known as the GTX-binding site, Ser-251 represents a novel site for GTX modification.

Quantitative evaluation of capacity-limited hepatobiliary transport based on hepatocellular diffusion model by MULTI(FEM)

The dose-dependency of hepatic uptake and hepatobiliary transport of a drug was evaluated by means of a nonlinear least square program incorporating the finite element method, MULTI(FEM). A perfusion experiment using isolated rat livers following a pulse input (i.e., under nonsteady-state conditions) was performed at three dose levels of cefpiramide as a model drug. The hepatic extraction ratio (E(H)) of cefpiramide decreased with an increase in dose, which demonstrates that the hepatic uptake is capacity-limited. The outflow time-profiles from the liver were represented by a two-compartment dispersion model with central Michaelis-Menten elimination, and the maximal elimination rate per central compartment volume (Vmax) and the Michaelis constant (Km) were estimated to be 1420 microg/ml/min and 235 microg/ml, respectively. The biliary mean transit time (t(bile)) increased slightly with an increase in dose. The hepatocellular diffusion model under non-steady-state conditions considering nonlinear transport across the bile canalicular membrane was adopted to evaluate dose-dependency in the biliary excretion of cefpiramide. The maximal penetration velocity across the bile canalicular membrane per liver (V=(bcm)max) and the affinity constant of penetration across the bile canalicular membrane (k(bcm)m = K(bcm)m A(H)L) were estimated to be 40.1 microg/min and 123 microg, respectively. Considering that the volume of a rat liver (A(H)L) is approximately 10 ml, the Michaelis constant of penetration (K(bcm)m), which is an apparent parameter, was estimated to be approximately 12.3 microg/ml. In conclusion, MULTI(FEM) is useful for evaluation of capacity-limited local disposition.

Effect of intermittent cyclical treatment with etidronate disodium (HEBP) and calcium plus alphacalcidol in postmenopausal osteoporosis

We evaluated intermittent cyclical treatment with etidronate disodium (HEBP) and calcium plus alphacalcidol in postmenopausal osteoporosis, with special reference to bone mineral density (BMD) and prevention of spinal fracture. The patients were 40 women, over 50 years of age, with lumbo-dorsal pain and low BMD (less than 0.70 g/cm(2)), measured by dual-energy X-ray absorptiometry (DXA). The patients were randomly assigned to two groups. The first group (HEBP) received 200 mg of HEBP per day for 2 weeks, followed by 2 g calcium lactate and 0.5 microg alphacalcidol per day for the next 10 weeks. This 12-week cycle was repeated eight times for 2 years. The second group (Ca. D) received 2 g calcium lactate and 0.5 microg alphacalcidol per day for 2 years. Lumbar BMD was measured before the treatment and every 6 months during the treatment until 24 months, and changes were evaluated. The number of fractured vertebrae was counted on X-ray films before treatment and at the final assessment. After 6 months of treatment, a significant and continuous increase in BMD was observed in the HEBP group. Moreover, the percentage of patients with new vertebral compression fractures in the HEBP group was one-tenth of that in the Ca. D group. These results suggest that intermittent cyclical treatment with HEBP and calcium plus alphacalcidol may be effective for increasing BMD and preventing fractures in postmenopausal osteoporosis.

Test validity of periodic liver function tests in a population of Japanese male bank employees

The validity (sensitivity and specificity) of annual liver function tests, determined by assaying blood levels of aspartate aminotransferase, alanine aminotransferase and gammaglutamyl transpeptidase, was evaluated using the results of health checkups of male bank workers. The specificity of each liver function test to detect persons with fatty liver, excess alcohol users, and hepatic virus carriers, diagnosed respectively by ultrasound, detailed inquiry, and virus marker tests, was always higher than 80%, except for alanine aminotransferase in excess alcohol users (63.5%). However, the highest sensitivity to detect virus carriers was alanine aminotransferase to detect HCV antibody-positive workers, but it was only 45.5%. The highest sensitivity of the liver function tests to detect excess alcohol users in obese subjects was only 33.3%. The highest sensitivity by liver function tests to detect fatty liver was 35.7% which was inferior to that of the body mass index. These results indicate that the liver function tests mandated in the workplace periodic health checkups in Japan exhibit very low sensitivity for the detection of any of the proposed target clinical conditions.

Transport characteristics of ebastine and its metabolites across human intestinal epithelial Caco-2 cell monolayers

The transport characteristics of a selective peripheral H1 receptor antagonist, ebastine, a substrate for cytochrome P450 3A4, and its three major metabolites, i.e., the hydroxy metabolite of ebastine (M-OH), the pharmacologically active metabolite carebastine (Car), and the desbutyrophenone metabolite (des-BP), were studied in cultured human intestinal Caco-2 cells expressing a drug efflux pump, P-glycoprotein (P-gp), on the apical membrane. The polarized transport of [3H]cyclosporin A (CyA), mediated by P-gp in the basolateral to apical direction across the Caco-2 cell monolayers, was affected by the presence of ebastine in a concentration-dependent manner and significant inhibition was observed at high concentrations (>50 microM). M-OH (300 microM) also significantly inhibited whereas Car and des-BP did not. Although no marked polarized transport of [14C]ebastine in a secretory direction was observed in the Caco-2 systems, the flux in the basolateral to apical direction was slightly higher than that in the opposite direction at concentrations less than 30 microm. [14C]Ebastine (2 microM) uptake from the apical side was significantly increased in the presence of an excess of cold CyA, suggesting that the efflux process mediated by P-gp may be involved in the ebastine uptake by Caco-2 cells. Collectively, these results indicate that ebastine (and presumably M-OH) is transported via P-gp in Caco-2 cells, however, the affinity for P-gp is very low. It is unlikely that the secretory transport of ebastine mediated by P-gp will dramatically affect overall intestinal absorption in vivo because efficient passive diffusion of this drug should occur due to its high lipophilicity. However, it may be advantageous for its efficient first-pass metabolism.

State-dependent action of grayanotoxin I on Na(+) channels in frog ventricular myocytes

1. Distinct properties of grayanotoxin (GTX) among other lipid-soluble toxins were elucidated by quantitative analysis made on the Na(+) channel in frog ventricular myocytes. 2. GTX-modified current (I(GTX)) was induced strictly in proportion to the open probability of Na(+) channels during preconditioning pulses irrespective of its duration, amplitude or partial removal of inactivation by chloramine-T. This confirms that GTX binds to the Na(+) channel exclusively in its open state, while batrachotoxin (BTX) was reported to be capable of modifying slow-inactivated Na(+) channels, and veratridine exhibited voltage-dependent modification. 3. The GTX-modified channel did not show any inactivation property, which is different from reported results with veratridine and BTX. 4. Estimated unbinding rates of GTX were in reverse proportion to the activation curve of GTX-modified Na(+) channels. This was not the previously reported case with veratridine. 5. A model including unbinding kinetics of GTX and slow inactivation of unmodified Na(+) channels in which GTX was permitted to bind only to the open state of Na(+) channels indicated that unbinding reactions of GTX occur only in the closed state.

Vitamin D receptor gene polymorphism is associated with serum total and ionized calcium concentration

Restriction fragment length polymorphisms of the vitamin D receptor gene have recently been reported to be associated with changes in bone mineral density. Alterations in systemic calcium balance and Ca-regulating hormones such as 1,25(OH)2 vitamin D3 and parathyroid hormone have been demonstrated in essential hypertension. We investigated the relationship between polymorphisms of the vitamin D receptor gene and systemic Ca metabolism in patients with essential hypertension and in normotensives. We compared 147 subjects with essential hypertension and 100 normotensive control subjects. The genotype distribution and derived allele frequencies for the vitamin D receptor gene were similar in the two groups (genotype bb/Bb/BB and allele B/b: 60.1/32.6/7.2 and 0.24/0.76 in hypertensives vs. 56.0/36.0/8.0 and 0.26/0.74 in normotensive subjects). Serum concentrations of total Ca in the bb, Bb, and BB groups were, respectively, 4.5+/-0.3 vs. 4.5+/-0.4 vs. 4.4+/-0.5 mmol/l in normotensives and 4.6+/-0.3 vs. 4.6+/-0.4 vs. 4.4+/-0.5 mmol/l in hypertensives. Ionized Ca levels were 1.17+/-0.04 vs. 1.16+/-0.04 vs. 1.15+/-0.04 mmol/l in normotensives and 1.16+/-0.04 vs. 1.16+/-0.04 vs. 1.14+/-0.05 mmol/l in hypertensives, respectively. These results indicate that the BB genotype of the vitamin D receptor gene is associated with lower serum Ca levels but is not a useful predictive marker for the development of essential hypertension in Japanese subjects.

Hepatic uptake and gene expression mechanisms following intravenous administration of plasmid DNA by conventional and hydrodynamics-based procedures

Hepatic uptake and gene expression mechanisms following intravenous administration of naked plasmid DNA (pDNA) by conventional and hydrodynamics-based procedures were studied in mice. After conventional (normal) intravenous injection, (32)P-labeled pDNA was rapidly eliminated from the circulation and predominantly taken up by the liver nonparenchymal cells while no significant gene expression was observed in this organ. The hepatic uptake process was saturable. Involvement of a specific mechanism was demonstrated since the hepatic uptake of [(32)P]pDNA was dramatically inhibited by cold pDNA, calf thymus DNA, and some polyanions [polyinosinic acid (poly I), dextran sulfate], but not by others (polycytidylic acid, chondroitin sulfate). The liver endothelial cells appeared to be a major contributor because gadolinium chloride (GdCl(3))-induced Kupffer cell blockade did not affect the hepatic uptake. After intravenous injection of naked pDNA with a large volume of saline at a high velocity (hydrodynamics-based procedure), the apparent hepatic uptake profile was similar to that after normal injection. The hepatic uptake was not inhibited by prior administration of polyanions, including poly I, dextran sulfate, and heparin. The hydrodynamics-based procedure resulted in marked gene expression in the liver, which was not inhibited by prior administration of polyanions or GdCl(3) treatment. These results indicate that pDNA uptake is a nonspecific process. This hypothesis was supported by the finding that significant hepatic uptake of bovine serum albumin and immunoglobulin G was observed after the hydrodynamics-based procedure.

Novel wasp toxin discriminates between neuronal and cardiac sodium channels

Pompilidotoxins (PMTXs), derived from the venom of solitary wasp has been known to facilitate synaptic transmission in the lobster neuromuscular junction, and a recent further study from rat trigeminal neurons revealed that the toxin slows Na+ channel inactivation without modifying activation process. Here we report that beta-PMTX modifies rat brain type II Na+ channel alpha-subunit (rBII) expressed in human embryonic kidney cells but fails to act on the rat heart alpha-subunit (rH1) at similar concentrations. We constructed a series of chimeric mutants of rBII and rH1 Na+ channels and compared modification of the steady-state Na+ currents by beta-PMTX. We found that a difference in a single amino acid between Glu-1616 in rBII and Gln-1615 in rH1 at the extracellular loop of D4S3-S4 is crucial for the action of beta-PMTX. PMTXs, which are small peptides with 13 amino acids, would be a potential tool for exploring a new functional moiety of Na+ channels.

[Topics of clinical physiological tests--pulmonary function--proposal of physio-chemical tests]

Pulmonary functions are classified as respiratory and non-respiratory. Although the mechanisms of non-respiratory pulmonary function have already been established, no new tests of respiratory pulmonary function have been developed for a long time. Thus, we report here a new analytic test of respiratory pulmonary functions. The new analytic method is physio-chemical analysis, in which the chemical factors of lungs are estimated from the physiological characteristics of lung during respiration. As examples, this report shows the method of exchanging mechanical energy to chemical energy in a comparison of lung ventilatory work between smokers and non-smokers. This report discusses the relationship between chemical energy and ATP in the blood of pneumoconiosis patients.

Response of the stroke volume and blood pressure of young patients with nonobstructive hypertrophic cardiomyopathy to exercise

Stroke volume (SV), cardiac output (CO) and systolic blood pressure (SBP) were measured during maximal symptom-limited bicycle exercise testing in 13 young patients (age, 11-26 years) with nonobstructive hypertrophic cardiomyopathy (HCM). SV was measured by impedance plethysmocardiography; %SVend, %COend, and %SBPend represent the ratio of the value at termination of the exercise to the respective value at rest. In all patients of HCM-I (the Cardiac Event Group, 3 patients) and 3 of HCM-II (the Non-Cardiac Event Group, 10 patients), the %SVend was less than 100%. The %SVend of HCM-I was significantly lower than the respective values of the HCM-II and Control groups. The %COend values of the HCM-I and HCM-II groups were each significantly lower than that of the Control. The %SBPend values of the HCM-I and HCM-II groups were each significantly lower than that of the Control. Among the HCM patients, the %SVend value was positively correlated with the %SBPend value. The patients who had more severe HCM had poorer exercise-induced increases in SV and SBP. These results suggest that sudden cardiac death in young HCM patients is associated with inhibition of the increase in SV upon exercise.

Localization of human airway trypsin-like protease in the airway: an immunohistochemical study

Human airway trypsin-like protease (HAT) has been isolated from mucoid sputum of patients with chronic airway diseases. In order to clarify the cellular source of this novel protease in the human airway, we examined the localization of immunoreactive HAT in bronchial tissues obtained at surgery and fixed in 4% paraformaldehyde using an extremely sensitive immunohistochemical technique called a catalyzed signal amplification method and a monoclonal antibody against recombinant HAT. HAT immunoreactivity was demonstrated in cytoplasm of ciliated cells of bronchial epithelium and/or at the basal part of cilia. No positive reaction was found in submucosal glands or mast cells. The heterogeneous distribution of HAT immunoreactivity within the bronchial epithelium indicates that its expression might be changeable and that it might be closely related to the physiological status of the airway epithelium. Non-specific but intense reaction caused by endogenous avidin-binding activity (EABA) was selectively detected in submucosal glands, but was effectively blocked by successive treatments with avidin and biotin. These results indicate that HAT may be synthesized in the ciliated cells and that it may play some physiological roles within the epithelial layer and on the airway surface. It is necessary to keep in mind that some cells show strong EABA, especially when a highly sensitive immunohistochemical technique is applied.

Novel mechanism of blocking axonal Na(+) channels by three macrocyclic polyamine analogues and two spider toxins

1. The mechanism of Na(+) channel block by three macrocyclic polyamine derivatives and two spider toxins was studied with voltage clamp and internal perfusion method in squid axons. 2. All these chemicals specifically block Na(+) channels in the open state only from the internal surface, and do not affect K(+) channels. 3. The blocking effect is enhanced as the depolarizing pulse becomes larger. Blocked channels are unable to shift to the inactivated state. 4. In the case of cyclam and guanidyl-side armed cyclam (G-cyclam), quick release of these chemicals from the binding sites is proven by the increase in the tail current and prolongation of the time course of the off gating current. On the other hand, in the presence of N-4 and the spider toxins, their detachment was delayed significantly. 5. Molecular requirements for the block of Na(+) channels by these molecules are the presence of positive charge and hydrophobicity.

Prevention of type I diabetes by low-dose gamma irradiation in NOD mice

Pretreatment with nonlethal, low-dose irradiation has been shown to have a protective effect against oxidative injury in animal tissues. Since oxidative injury of tissues is known to be a major cause of many human diseases, we examined the effect of low-dose irradiation on the progression of type I diabetes in mice. Nonobese diabetic (NOD) mice were treated with gamma irradiation and the progression of the disease was monitored. An elevated level of glucose in urine was first detected at 15 weeks of age in the control NOD mice, whereas the detection was delayed as long as 7 weeks when the mice received a single dose of 0.5 Gy total-body irradiation between 12 and 14 weeks of age. The greatest effect was observed in the mice irradiated at 13 weeks of age. The increase in blood glucose and decrease in blood insulin were effectively suppressed by irradiation at 13 weeks of age. Both suppression of cell death by apoptosis and an increase in superoxide dismutase (SOD) activity were observed in the pancreas 1 week after irradiation. The results indicate that treatment with 0.5 Gy gamma rays suppresses progression of type I diabetes in NOD mice. This is the first report on the preventive effect of low-dose irradiation on disease progression.

Possible role of elevation of glutathione in the acquisition of enhanced proliferation of mouse splenocytes exposed to small-dose gamma-rays

PURPOSE

To examine the relation between the induction of an increased glutathione level and the elevated proliferative response of mouse splenocytes by a small dose of gamma-rays.

MATERIALS AND METHODS

Male ICR strain mice, 7 weeks of age, were divided into irradiated and non-irradiated control groups. Irradiation was done with gamma-rays from a 137Cs source at a dose of 50 cGy (1.11 Gy/min). Glutathione content in the splenocytes was measured using a modified spectrophotometric technique. Concanavalin A (Con A)-induced proliferative response of the splenocytes after whole-body gamma-ray irradiation was estimated from the 3H-thymidine incorporation into the cells.

RESULTS

The glutathione level in mouse splenocytes increased 2 h after whole-body y-ray irradiation at 50cGy, peaked at 4h and thereafter decreased almost to the zero-time level by 12-h postirradiation. A significant enhancement of Con A-induced proliferation was observed in the splenocytes obtained from the whole-body-irradiated animals between 2h and 6h post-irradiation. Glutathione exogenously added to splenocytes obtained from normal mice enhanced the Con A-induced proliferation of splenocytes in a dose-dependent manner. This enhancement was completely blocked by buthionine sulfoximine, a specific inhibitor of the de novo pathway of glutathione synthesis.

CONCLUSIONS

The induction of endogenous glutathione immediately after low-dose gamma-ray irradiation is at least partially responsible for the enhancement of immune function, and may throw light on the mechanisms of carcinostatic effects induced by low dose ionizing radiation.

A computational model for quantitative analysis of cell cycle arrest and its contribution to overall growth inhibition by anticancer agents

Most anticancer agents induce cell cycle arrest (cytostatic effect) and cell death (cytotoxic effect), resulting in the inhibition of population growth of cancer cells. When asynchronous cells are to be examined, the currently used flow cytometric method can not provide checkpoint-specific and quantitative information on the drug-induced cell cycle arrest. Hence, despite its significance, no good method to analyze in detail the mechanism of cell cycle arrest and its contribution to overall growth inhibition induced by an anticancer agent has yet been established. We describe in this study the development of a discrete time (Markov model)-based computational model for cell cycle progression / arrest with transition probability (TP(i)) as a model parameter. TP(i) was calculated using model equations that include easily measurable parameters such as the fraction of cells in each cell cycle phase and population doubling time. The TP(i) was then used to analyze checkpoint-specific and quantitative changes in cell cycle progression. We also used TP(i) in a Monte-Carlo simulation to predict growth inhibition caused by cell cycle arrest only. Human SCLC cells (SBC-3) exposed to UCN-01 were used to validate the model. The model-predicted growth curves agreed with the observed data for SBC-3 cells not treated or treated at a cytostatic concentration (0.2 mM) of UCN-01, indicating validity of the present model. The changes in TP(i) indicated that UCN-01 reduced the G(1)-to-S transition rate and increased the S-to-G(2) / M and G(2) / M-to-G(1) transition rates of SBC-3 cells in a concentration- and time-dependent manner. When the model-predicted growth curves were compared with the observed data for cells treated at a cytotoxic concentration (2 mM), they suggested that 22% out of 65% and 32% out of 73% of the growth inhibition could be attributed to the cell cycle arrest effect after 48 h and 72 h exposure, respectively. In conclusion, we report here the establishment of a novel method of analysis that can provide checkpoint-specific and quantitative information about cell cycle arrest induced by an anticancer agent and that can be used to assess the contribution of cell cycle arrest effect to the overall growth inhibition.

Involvement of calcium ion in elevation of mRNA for gamma-glutamylcysteine synthetase (gamma-GCS) induced by low-dose gamma-rays

PURPOSE

To investigate the mechanism of the intracellular glutathione elevation induced by low-dose gamma-radiation.

MATERIALS AND METHODS

RAW 264.7 cells were irradiated with 1-400cGy gamma-rays. Intracellular total glutathione content was determined by DTNB-recycling assay. Expression of mRNA for intracellular glutathione synthesis-related enzymes with or without treatment with various inhibitors of second messengers of gene expression were examined by Northern blot analysis.

RESULTS

Expression of mRNA for gamma-glutamylcysteine synthetase (gamma-GCS), a rate-limiting enzyme of the de novo glutathione synthesis pathway, was elevated much more than that of glutathione reductase (GR) mRNA after exposure to 50cGy gamma-rays. The low-dose gamma-ray-induced gamma-GCS mRNA elevation was abolished by inhibitors of protein kinase C and protein tyrosine kinase, as well as by the calcium ion channel blocker, nifedipine. Calcium-related reagents, such BAPTA/AM and EGTA, chelators of intra- and extracellular Ca2+ respectively, and a Ca2+ ionophore (A23187), also strongly blocked the elevation of gamma-GCS mRNA expression induced by gamma-rays.

CONCLUSIONS

The increase of intracellular glutathione in RAW 264.7 soon after low-dose gamma-ray exposure mainly occurs through the operation of the de novo pathway, following by the induction of gamma-GCS mRNA, for which elevation of intracellular calcium is required.

One-step purification of rabbit histidine rich glycoprotein by dye-ligand affinity chromatography with metal ion requirement

A simple method for purification of the histidine rich glycoprotein (rHRG) from rabbit sera was developed. The rHRG was purified by one-step affinity chromatography using the triphenylmethane dye "acid fuchsin" as a specific ligand, which gave an overall yield above 80%. Interestingly, the binding of rHRG to the ligand required the divalent transition-metal ions such as Zn2+, Ni2+, and Co2+ at pH 9.5. In the presence of 0.5 mM ZnCl2, the binding was enhanced 15 times compared with that in the absence of ZnCl2. Bound rHRG was efficiently eluted from the affinity absorbent with 100 mM imidazole or histidine. Purified rHRG was homogeneous with an Mr of 94 kDa when analyzed by SDS-PAGE, whereas isoelectric focusing revealed microheterogeniety with pI values ranging from 6.3 to 6.8. Blotting analysis with lectins specific for carbohydrate moieties and treatment with glycosidases demonstrated that rHRG is a highly N-glycosylated protein with diverse carbohydrate structures.

Electrooptics of beta-FeOOH Particles in Aqueous Media

Reversing-pulse electric birefringence (RPEB) of a nearly monodisperse iron(III) hydroxide oxide sample in the beta-form (beta-FeOOH) was measured at 25 degrees C and at a wavelength of 633 nm in aqueous media in the presence of NaCl. The concentrations of beta-FeOOH and added NaCl varied between 0.00111 and 0.0555 g/L and 0.03 and 2.0 mM, respectively. Except for the suspensions with high salt concentrations, each RPEB signal showed a dip or minimum in the reverse process upon electric field reversal, together with a smooth rise in the buildup and a fall in the decay process. The observed signals were analyzed with a new RPEB theory, which takes into account not only the permanent electric dipole moment (µ) but also the root-mean-square ionic dipole moment (<m(2)>(1/2)) due to the ion fluctuation in ion atmosphere, in addition to the field-induced electronic (covalent) dipole moment Deltaalpha' E. The results showed that the slowly fluctuating moment of <m(2)>(1/2) is by far the most predominant one for the field orientation of the beta-FeOOH particle, though the permanent dipole moment µ may not be completely excluded. The rotational relaxation time of the whole particle was evaluated from the decay signal, while the relaxation time for fluctuating ions was estimated from RPEB signal fitting. The sign of the steady-state birefringence for beta-FeOOH suspensions was positive without exception under the present conditions. The birefringence signals in the steady state (delta/d) were proportional to the second power of the applied field strength (E) in the low field region; thus, the Kerr law was verified to hold for beta-FeOOH suspensions. The specific Kerr constant was evaluated for each suspension by extrapolating the values of delta/d to zero field (E-->0). Copyright 2000 Academic Press.

An analysis of the variations in potency of grayanotoxin analogs in modifying frog sodium channels of differing subtypes

Responses of tetrodotoxin-sensitive (TTX-s) and insensitive (TTX-i) Na(+) channels, in frog dorsal root ganglion (DRG) cells and frog heart Na(+) channels, to two grayanotoxin (GTX) analogs, GTX-I and alpha-dihydro-GTX-II, were examined using the patch clamp method. GTX-evoked modification occurred only when repetitive depolarizing pulses preceded a single test depolarization; modification, during the test pulse, was manifested by a decrease in peak Na(+) current accompanied by a sustained Na(+) current. GTX-evoked modification of whole-cell Na(+) currents was quantified by normalizing the conductance for sustained currents through GTX-modified Na(+) channels to that for the peak current through unmodified Na(+) channels. The dose-response relation for GTX-modified Na(+) channels was constructed by plotting the normalized slope conductance against GTX concentration. With respect to DRG TTX-i Na(+) channels, the EC(50) and maximal normalized slope conductance were estimated to be 31 microM and 0.23, respectively, for GTX-I, and 54 microM and 0.37, respectively, for alpha-dihydro-GTX-II. By contrast, TTX-s Na(+) channels in DRG cells and Na(+) channels in ventricular myocytes were found to have a much lower sensitivity to both GTX analogs. In single-channel recording on DRG cells and ventricular myocytes, Na(+) channels modified by the two GTX analogs (both at 100 microM), had similar relative conductances (range, 0.25-0.42) and open channel probabilities (range, 0.5-0.71). From these observations, we conclude that the differences in responsiveness of DRG TTX-i, and ventricular whole cell Na(+) currents to the GTX analogs studied are related to the number of Na(+) channels modified.

[Prophylactic efficacy of a basidiomycetes preparation AHCC against lethal opportunistic infections in mice]

The prophylactic effects of a Basidiomycetes preparation, AHCC, against experimental opportunistic infections were investigated in leukopenic mice. In cyclophosphamide-induced leukopenic mice, oral or intraperitoneal administration of the AHCC at doses of 1000 or 50 mg/kg/day, respectively, for 4 consecutive days prior to Candida albicans infection significantly prolonged the survival periods of the infected mice, and decreased the viable counts of C. albicans cells recovered from their kidneys. Similarly, the oral treatment with AHCC protected mice from lethal infection with Pseudomonas aeruginosa and intraperitoneal one also protected mice from infection with methicillin-resistant Staphylococcus aureus (MRSA). These results suggest a potential usefulness of the AHCC as a prophylactic agent for the management of patients with opportunistic infections.

Platelet-activating factor acetylhydrolase gene mutation in Japanese children with Escherichia coli O157-associated hemolytic uremic syndrome

Platelet-activating factor (PAF) may be involved in the pathogenesis of Escherichia coli O157-associated hemolytic uremic syndrome (HUS). PAF is degraded to inactive products by PAF acetylhydrolase. In this study, we investigated whether a PAF acetylhydrolase gene mutation (G-->T transversion at position 994) is involved in HUS in Japanese children. A point mutation in the PAF acetylhydrolase gene (G994T) was identified using polymerase chain reaction in 50 Japanese children with E coli O157-associated HUS and 100 healthy Japanese. We then determined the relationship between the PAF acetylhydrolase G994T gene mutation and clinical features of HUS. There was no difference in genotype and allele frequencies between patients with HUS and healthy controls. The mean duration of oligoanuria was significantly longer in patients with the GT genotype than in those with the GG genotype (P = 0.012). Although 11 of 15 patients (73%) heterozygous for the mutant allele (GT) required dialysis, only 13 of the 35 wild-type homozygotes (GG; 37%) required dialysis (P = 0. 030). Mean plasma PAF acetylhydrolase activity was significantly less in patients with the GT genotype than in those with the GG genotype (P < 0.0001). In conclusion, we have shown an association between the G994T PAF acetylhydrolase gene mutation and the severity of renal damage in E coli O157-associated HUS. Our study suggests that analysis of the PAF acetylhydrolase gene mutation in Japanese children with E coli O157-associated HUS may allow the prediction of the severity of HUS.

Effect of sulfhydryl reagents on the regulatory system of the L-type Ca channel in frog ventricular myocytes

The effects of sulfhydryl (SH) reagents on the L-type Ca current (ICa) were studied in frog ventricular myocytes using the whole-cell patch-clamp method. Methanethiosulfonate ethylammonium (MTSEA+) was found to enter the cell through the membrane and cause a remarkable increase in Ica from the intracellular side. Methanethiosulfonate ethyltrimethylammonium (MTSET+) and methanethiosulfonate ethylsulfonate (MTSES-) could not penetrate the membrane and were effective only when directly applied to the intracellular side. In addition, suppressive effects on ICa of these MTS reagents were indicated by the following observation. A progressive decay in the peak amplitude of ICa after establishing maximal ICa, stimulated by intracellular MTSET+, was prevented by adding extracellular dithiothreitol (DTT). The SH-oxidizing agents N-ethylmaleimide (NEM), chloramine-T (CL-T), 2,2'-dithiodipyridine (DTDP) and 2,2'-dithio-bis-5-nitropyridine (DTBNP) also exerted a stimulatory effect on Ica. The effect of SH reagents persisted even when cAMP production was inhibited with Rp-cAMP-S, or when G-protein was inhibited with 1 mM GDPbetaS, indicating that the effect is not due to cAMP production or G-protein stimulation. It is concluded that there are sites on the Ca channels that are subject to direct modification by SH reagents.

Mechanisms involved in the elevation of glutathione in RAW 264.7 cells exposed to low doses of gamma-rays

We examined the mechanisms of the elevation of glutathione level induced in macrophage-like RAW 264.7 cells by low doses of gamma-rays. The level increased soon after exposure of the cells to 50 cGy of gamma-rays, peaked between 3 hours and 6 hours and returned almost to the time 0 value by 24 hours post-irradiation. Doses between 25 and 100 cGy significantly increased the glutathione level at 4 hours post-irradiation. However, there was no significant elevation at doses of more than 100 cGy or less than 25 cGy. When the effect of dose rate was examined at a constant absorbed dose of 50 cGy, dose rates of more than 50 cGy/minute significantly increased the GSH level at 4 hours post-irradiation. It was also shown that the elevation of glutathione level in cells irradiated with low doses of gamma-rays followed the induction of mRNA coding for gamma-glutamylcysteine synthetase (gamma-GCS), a rate-limiting enzyme of the de novo glutathione synthesis pathway. When the cells were exposed to the radiation in the presence of genistein, calphostin C or nifedipine, the elevations of glutathione and gamma-GCS mRNA expression were both mostly blocked. EGTA also strongly inhibited these elevations. These results suggest that the tyrosine kinase, calcium channel and protein kinase C activities play an essential role in the low-dose-radiation-induced elevation of cellular glutathione.

Pulsed Electric Linear Dichroism of Triphenylmethane Dyes Adsorbed on Montmorillonite K10 in Aqueous Media

Electric linear dichroism (ELD) spectra of two cationic triphenylmethane dyes, crystal violet (CV) and malachite green (MG), bound to sodium montmorillonite K10 (MK-10) were studied at 20 degrees C in aqueous media at two mixing ratios, D/S, of 0.10 and 0.24 in the 700- to 400-nm wavelength region and in the applied electric field strength range between 0 and 3 kV/cm. The specific parallel and perpendicular dichroism (Delta A( ||)/A and Delta A( perpendicular)/A) spectra of dye-adsorbed MK-10 suspension were measured at a fixed field strength with an apparatus equipped with a 512-channel photodiode array detector. By changing the field strength over a wide range, a series of the reduced dichroism values of the bound dyes were measured at a fixed wavelength. By fitting these dichroism values to theoretical orientation functions, the intrinsic reduced dichroism (Delta A/A)(int) spectra at the limiting high fields (ELD spectrum) were determined for CV and MG bound to MK-10. No appreciable difference was observed at the two D/S values. The ELD spectra of these bound dyes are undulatory but never constant, throughout their absorption region; thus, the dye plane does not lie flatly either on the surface or between layers of MK-10 particle. The isotropic absorption spectra, A, of bound CV and MG were each deconvoluted to eight partial absorption bands, which were grouped into three differently polarized transitions, i.e., one out-of-plane and two mutually perpendicular in-plane. The optical transition dipole moment direction of each group was found to make a considerable angle with respect to the symmetry axis of the disklike MK-10 particle, whose plane (or surface) tends to orient toward the applied electric field at the limiting high fields. By simulating the observed ELD spectra of bound CV and MG with those deconvoluted bands, the roll, tilt, and inclination angles of both dyes were evaluated quantitatively with a new analytical method. The average angles (+/-&theta;(R), +/- &theta;(T), |&theta;(N)|) are -(34-47) degrees, 34 degrees, and 51 degrees for bound CV and -44 degrees, 32 degrees, and 53 degrees for bound MG at two D/S values; thus, the triangular plane of each dye is rolled as well as tilted with a large inclination angle. Copyright 2000 Academic Press.

Expression of gap junction protein connexin 32 in chronic liver diseases

BACKGROUND

Gap junctions contain intercellular channels through which contacting cells communicate directly. The expression of connexin 32, a major gap junction protein in the liver, during the progression of chronic liver diseases has not yet been clarified.

METHODS

Immunohistochemical staining was performed using anti-connexin 32 antibody on 6 specimens of normal human liver, 7 of chronic viral hepatitis, and 7 of liver cirrhosis.

RESULTS

The number of gap junction plaques in chronic viral hepatitis and liver cirrhosis was significantly smaller than that in normal liver (10350+/-2180 and 7550+/-3040 vs 22560+/-3700 spots/mm2, p<0.01). The number of gap junction plaques tended to be lower in liver cirrhosis than in chronic viral hepatitis.

CONCLUSION

These results suggest that in chronic liver diseases impaired intercellular communication between hepatocytes occurs.

Expression of galectin-1 mRNA correlates with the malignant potential of human gliomas and expression of antisense galectin-1 inhibits the growth of 9 glioma cells

Although its precise function has not yet been established, galectin-1 seems to play a role in tumor progression. In this study, we investigated galectin-1 mRNA expression in human glioma specimens and glioma cell lines. Northern blot analysis showed higher galectin-1 mRNA levels in glioma tissues. The 0.7-kb galectin-1 mRNA transcript was detected, and the expression level correlated with the malignant state, from low-grade astrocytoma to glioblastoma. In several human glioma specimens, immunohistochemical examination with antiserum against a synthetic peptide corresponding to the predicted C-terminal sequence of the protein showed high levels of galectin-1 expression. To clarify the correlation between the expression of galectin-1 and the malignancy of gliomas, we examined whether expression of antisense galectin-1 would suppress tumor growth in rat 9L cells that express high levels of galectin-1. The cells were transfected with a plasmid DNA that produces antisense galectin-1 mRNA under the control of the metallothionein promoter, and stable clones expressing low levels of galectin-1 protein in comparison with control clones were isolated. Cells with low levels of galectin-1 displayed dramatic phenotypic changes in their morphology and growth properties compared with vector-transfected control 9L cells. Our data suggest that decreased expression of galectin-1 may arrest the growth of rat 9L cells.

Inhibitory effects of post low dose gamma-ray irradiation on ferric-nitrilotriacetate-induced mice liver damage

We studied the effects of a single post whole-body low-dose irradiation (50 cGy of gamma-ray) on mice with ferric nitrilotriacetate (Fe3+-NTA)-induced transient hepatopathy. As a result, low-dose irradiation accelerated the rate of recovery. Based on the changes in glutamic oxaloacetic transaminase (GOT) activities, glutamic pyruvic transaminase (GPT) activities and lipid peroxide levels, it was shown that hepatopathy was improved by low-dose irradiation 3 h after Fe3+-NTA administration. This may be because of the enhancement of antioxidant agents such as total glutathione (GSH + GSSG), glutathione peroxidase (GPX), glutathione reductase (GR) and gamma-glutamylcysteine synthetase (gamma-GCS) by low-dose irradiation. These findings suggest that low-dose irradiation relieved functional disorders at least in the livers of mice with active oxygen species related diseases.

[Validity and reproducibility of a semi-quantitative food frequency questionnaire for nutritional education of patients of diabetes mellitus (FFQW65)]

BACKGROUND

A self-administered semi-quantitative food frequency questionnaire with 65 food lists (FFQW65) was developed for the nutritional education of patients of diabetes mellitus.

METHODS

Relative validity and reproducibility of nutrient intakes as assessed by FFQW65 were investigated in volunteers of 71 males. To assess the relative validity, a one-week diet record was used as a reference. The FFQW65 was administered twice at an interval of 10 month in order to assess the reproducibility. Log transformed data was used to obtain Pearson correlation coefficients.

RESULTS

As for the validity, Pearson correlation coefficient of total energy intake of breakfast was 0.74 and the relative difference between predicted value and diet record was relatively small (the difference was -5 kcal and relative difference rate was 1.1%). Compared with breakfast, those for lunch, supper and one-day total energy intakes were relatively lower (0.52, 0.66 and 0.64, respectively) and the relative differences were around 10%, respectively. The one-day intakes of sixteen nutrients (except for potassium and niacin) ranged from 0.28 to 0.64. Energy adjusted correlation coefficients for protein, iron and cholesterol were low (0.16, 0.14 and 0.19, respectively). Those for the other thirteen nutrients ranged from 0.26 to 0.65. As for the reproducibility, the second survey using FFQW65 was administered to 64 males. Pearson correlation coefficient of one-day total energy intake was 0.76 and those for the other nutrients ranged from 0.54 (vitamin D) to 0.81 (calcium).

CONCLUSION

The results suggest that FFQW65 can be used for the evaluation of energy intake by usual meals for nutrition education of patients of diabetes mellitus.

On site of action of grayanotoxin in domain 4 segment 6 of rat skeletal muscle sodium channel

Grayanotoxin I (GTX I) is a diterpenoid extracted from the family of Ericaceae that binds to Na(+) channels and causes persistent activation. We investigated the interaction of GTX I with the amino acid residues I1575, F1579 and Y1586 in transmembrane segment D4S6 of micro1. In F1579A, GTX shifted the threshold potential about 50 mV in the hyperpolarizing direction and modified Na(+) channels twice as efficiently as that in wild-type. In contrast, these GTX-effects were eliminated completely in the I1575A mutant and were reduced substantially in mutant Y1586A. Lysine substitution for F1579 significantly reduced and for Y1586 completely eradicated the GTX-effect. Our data suggest that the GTX receptor site shares overlapping but non-identical molecular determinants with BTX in D4S6 and has common molecular determinants in D1S6.