Biomedical subjects

S Uchino

Publications and source records attributed to S Uchino.

At least 37 records · Page 2Linked to original sources

PubMed2001

A serine protease inhibitor, N-alpha-tosyl-l-lysine chloromethyl ketone, prolongs rat hepatic allograft survival.

BACKGROUND: Serine protease inhibitors have profound suppressive effects on cellular and humoral immune responses. We investigated the effect of a serine protease inhibitor, N-alpha-tosyl-l-lysine chloromethyl ketone (TLCK), on hepatic allograft survival in rats. Methods. Orthotopic hepatic transplantation was performed in an ACI (RT1(a))-to-LEW (RT1(1)) rat combination. TLCK was administered continuously at a dose of 4.4 mg/kg/day using an osmotic subcutaneous infusion minipump. RESULTS: TLCK prolonged hepatic allograft survival. Histologic staging of acute rejection based on Banff criteria in TLCK-treated hepatic allografts was significantly lower than in untreated allografts. TLCK significantly reduced serum concentrations of interferon (IFN)-gamma and tumor necrosis factor (TNF) alpha in allograft recipients. TNF-alpha mRNA levels in TLCK-treated allografts were significantly lower than in untreated allografts. TLCK also decreased perforin mRNA levels in hepatic allografts. Hepatic infiltrates eluted from TLCK-treated allografts showed significantly lower cell-mediated lympholytic activity against donor Con A blast cervical lymph node cells than those from untreated allografts. In vitro, TLCK suppressed interleukin-2 production and [(3)H]thymidine incorporation into an allogeneic mixed lymphocyte reaction. CONCLUSION: TLCK suppressed acute allograft rejection, suggesting a novel immunosuppressive strategy for therapy of acute organ rejection.

Animals↗

PubMed2001

Differential splenic migration of dendritic cells after immunologic unresponsiveness in rat hepatic allografts induced by pretransplant donor-specific transfusion.

BACKGROUND: Donor dendritic cells migrate into the recipient spleen after hepatic transplantation. We previously reported that immunologic unresponsiveness to rat hepatic allografts can be induced by prior donor-specific blood transfusion (DST). We investigated the phenotype and splenic distribution of donor dendritic cells after allografting and DST. METHODS: Donor dendritic cells were identified with anti-rat dendritic cell (OX-62) and anti-donor class II MHC (RT1B(a)) (OX-76) antibodies. The phenotype of dendritic cells was determined with antibodies to CD45RC, CD62L, and the maturation markers CD80 (B7-1) and CD86 (B7-2). The cytokine profile of sorted CD45RC(+) OX-62(+) and CD45RC(-) OX-62(+) dendritic cells was analyzed by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Pretransplant DST significantly prolonged rat hepatic allograft survival. Immunostaining revealed OX76(+)/OX-62(+) cells in the splenic red pulp of animals receiving pretransplant DST and in the white pulp of untreated animals after transplantation. The ratio of splenic CD45RC(-) OX-62(+) cells to CD45RC(+) OX-62(+) cells was significantly higher in DST recipients than in untreated animals. CD62L, CD80, and CD86 were lower on CD45RC(-) OX-62(+) than CD45RC(+) OX-62(+) cells. RT-PCR revealed that sorted CD45RC(-) OX-62(+) cells expressed interleukin (IL)-4 and IL-10. In contrast, sorted CD45RC(+) OX-62(+) cells expressed only IL-2 and interferon gamma (IFN-gamma). CONCLUSION: Differential splenic migration of CD45RC(-) dendritic cells is associated with immunologic unresponsiveness to rat hepatic allografts.

Animals↗

PubMed2001

Usefulness of endoscopic ultrasonography (EUS) in diagnosing esophageal infiltration of thyroid cancer.

Pre-operative evaluation of esophageal infiltration is sometimes difficult in patients with advanced thyroid cancer even with recent imaging modalities. We evaluated the accuracy of endoscopic ultrasonography (EUS) in diagnosing esophageal infiltration of thyroid cancer. Twenty-nine patients with advanced thyroid cancer underwent EUS and other imaging examinations before surgery. The diagnostic accuracy of EUS was compared with that of magnetic resonance imaging (MRI) and esophagography based on pathologic findings in 27 of the 29 cases. EUS clearly demonstrated the 5-layer structure of the esophageal wall. EUS detected cancer invasion into the muscularis propria of the esophagus correctly in 8 of 10 patients diagnosed pathologically with muscular infiltration. EUS was significantly more accurate than MRI and esophagography (88.9% vs 63.0% and 66.7%, respectively). The specificity of EUS was also significantly better than the specificities of MRI or esophagography (94.1% vs 58.8% and 64.7%, respectively). The sensitivity, positive predictive value and negative predictive value of EUS tended to be better than those of MRI and esophagography. EUS is useful in evaluating the esophageal infiltration of thyroid cancer. This method has the further advantage of detecting the exact depth of cancer invasion into the esophageal wall.

Adenocarcinoma, Follicular↗

PubMed2001

Intermittent versus continuous renal replacement therapy in the ICU: impact on electrolyte and acid-base balance.

OBJECTIVES: The maintenance of normal serum sodium, potassium and bicarbonate concentrations is a therapeutic goal of renal replacement therapy (RRT) in acute renal failure (ARF). The aim of this study was to determine whether this goal is best achieved with intermittent hemodialysis (IHD) or continuous venovenous hemodiafiltration (CVVHDF). DESIGN: Retrospective controlled study. SETTING: Tertiary intensive care unit. PATIENTS: Consecutive patients with ARF treated with IHD (n = 47) or CVVHDF (n = 49). INTERVENTIONS: Measurement of daily morning sodium, potassium and bicarbonate concentrations after the initiation of RRT for up to 2 weeks of treatment. MEASUREMENTS AND RESULTS: Before RRT, abnormal (high or low) values were frequently observed for sodium (42.6% vs 39.6%; NS) potassium (23.4% vs 45.8%; NS) and bicarbonate (63.2 % vs 54.3 %; NS). After treatment, however, CVVHDF, but not IHD, significantly increased mean sodium concentrations (p = 0.0001). CVVHDF was also more likely to normalize the serum sodium than IHD (76.2 % vs 47.8% p = 0.0001). The mean potassium concentrations of both groups significantly decreased (p = 0.019 vs p = 0.0075, difference: NS). However, CVVHDF more frequently reduced the incidence of hypokalemia (1.9 % vs 7.1%, p = 0.0006). CVVHDF but not IHD significantly increased mean bicarbonate concentrations (p = 0.016) in the first 48 h, and more frequently normalized them (71.5% vs 59.2, p = 0.0073). CONCLUSIONS: Serum sodium and potassium, and arterial bicarbonate, concentrations are frequently abnormal in ARF patients before and during renal replacement. Normalization of these values, however, is achieved more frequently with CVVHDF than with IHD.

APACHE↗

PubMed2001

A single-channel method for evaluation of very magnitudes of Ca2+ ion fluxes through epsilon4/zeta1 N-methyl-D-aspartate receptor channels in bilayer lipid membranes.

A single-channel method for evaluating agonist selectivity in terms of the very number of Ca2+ ions passed through the epsilon4/zeta1 N-methyl-D-aspartate (NMDA) receptor ion channel in bilayer lipid membranes (BLMs) is described. The number of Ca2+ passed through the single-channel was obtained from single-channel recordings in a medium where the primary permeant ion is Ca2+. The recombinant epsilon4/zeta1 NMDA channel was partially purified from Chinese hamster ovary cells expressing the channel and incorporated in BLMs formed by the tip-dip method. It was found that the epsilon4/zeta1 channel in BLMs is permeable to Ca2+ and Na+, but the number of Ca2+ passed through the channel is much fewer than that of Na+. The integrated Ca2+ currents induced by three typical agonists NMDA, L-glutamate and L-CCG-IV were obtained at concentration of 50 microM, where the integrated currents for all the agonists reached their saturated values. The integrated Ca2+ currents obtained are (3.1+/-0.21) x 10(-13) C/s for NMDA, (4.6+/-0.31) x 10(-13) C/s for L-glutamate and (5.7+/-0.25) x 10(-13) C/s for L-CCG-IV, respectively, suggesting that the three kinds of agonists have different efficacies to induce permeation of Ca2+. The range of the agonist selectivity thus obtained is much narrower than that of binding affinities for the NMDA receptors from rat brain. The present method is able to detect Ca2+ permeation with a detection limit of approximately 10(5) Ca2+ ions/s.

Animals↗

PubMed2001

Predictive risk factors for postoperative tetany in female patients with Graves' disease.

BACKGROUND: Postoperative tetany occurs in patients with secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism induced by surgery. In the present study, we further clarified the risk factors by referring to serum 25-hydroxyvitamin D [25(OH)D] and alkaline phosphatase. STUDY DESIGN: The serum levels of intact parathyroid hormone, calcium and other electrolytes, and 25-hydroxyvitamin D [25(OH)D] were measured preoperatively in 178 female patients with Graves' disease who underwent subtotal thyroidectomy. RESULTS: Of the 178 female patients, 15 (8.4%) developed tetany. Univariate analysis of 16 possible risk factors showed that 2 were statistically significant: serum 25(OH)D and alkaline phosphatase levels. The incidence of tetany according to the serum levels of 25(OH)D and alkaline phosphatase was 19.1% (9/47) in patients with 25(OH)D < or = 25 nmol/L and alkaline phosphatase > 155, 11.8% (4/34) in those with 25(OH)D < or = 25 nmol/L and alkaline phosphatase < or = 155, 6.7% (2/30) in those with 25(OH)D > 25 nmol/L and alkaline phosphatase > 155, and 0% (0/50) in those with 25(OH)D > 25 nmol/L and alkaline phosphatase < or = 155. CONCLUSIONS: Patients with Graves' disease who have vitamin D deficiency with high serum alkaline phosphatase levels are the highest-risk group for postoperative tetany. Serum 25(OH)D and alkaline phosphatase should be monitored in patients with Graves' disease.

Adolescent↗

PubMed2001

Real-time, two-dimensional visualization of ischaemia-induced glutamate release from hippocampal slices.

The involvement of excitatory amino acid (EAA) toxicity in ischaemia-induced neuronal cell death has long been suggested. However, in the hippocampus, the brain site most vulnerable to ischaemia, the detailed spatial and temporal patterns of EAA release are not yet known. To address this issue, we have developed a novel strategy for the continuous, real-time, two-dimensional monitoring of EAA release from brain slices. As EAA detector, we used a cell line transformed with the N-methyl-D-aspartate (NMDA) receptor, which is exclusively activated by EAAs, leading to an increase in the intracellular Ca(2+) level. Combined with a calcium imaging technique, the use of this cell line allowed the temporal and regional analysis of EAA release from a brain slice placed directly on top of the clonal cells in a culture dish. Using this strategy, we demonstrated ischaemia-induced EAA release in rat hippocampal slices. Increased EAA release was seen initially in the CA1 region, about 3 min after the beginning of ischaemia, then in the CA3 region and dentate gyrus, and, finally, throughout the hippocampal slice. Regional differences in extracellular EAA levels were also seen, with more EAA being released from the CA1 region than from the middle dentate gyrus. The present results are especially interesting as neurons in the CA1 region are more vulnerable to ischaemia than those in the CA3 region and dentate gyrus.

Alanine↗

PubMed2001

CD45RC gammadelta T-cell infiltration is associated with immunologic unresponsiveness induced by prior donor-specific blood transfusion in rat hepatic allografts.

Little is known regarding the role of gammadelta(+) T cells in organ transplantation. We previously reported that immunologic unresponsiveness is induced by prior donor-specific blood transfusion (DST) in rat hepatic allografts. We investigated the phenotype and distribution of gammadelta(+) T cells in the hepatic allograft, spleen, and peripheral blood of recipient rats with immunologic unresponsiveness induced by DST. gammadelta(+) T cells were enumerated in allograft livers and spleens by immunostaining and in blood by flow cytometric analysis. The phenotype of gammadelta(+) T cells was determined using CD45RC isoforms derived from alternative mRNA splicing. The cytokine profile of CD45RC(+) and CD45RC(-) gammadelta(+) T cells was analyzed by reverse transcription polymerase chain reaction. The number of gammadelta(+) T cells in hepatic infiltrates in recipient rats pretreated with DST was significantly greater than in untreated animals. This correlated with significantly higher levels of gammadelta T cell receptor (TCR) mRNA in hepatic allografts of DST-treated rats as compared with untreated animals. The gammadelta(+) T cell/alphabeta(+) T-cell ratio increased in hepatic infiltrates in DST-treated recipient rats but not in untreated animals. CD45RC(-)gammadelta(+) T cells were predominantly increased in DST-treated hepatic allografts compared with untreated allografts. Most of the intestinal intraepithelial T cells were CD45RC(-)gammadelta(+). Interleukin (IL)-10 and IL-4 mRNA were detected more in CD45RC(-)gammadelta(+) T cells than CD45RC(+)gammadelta(+) T cells. CD45RC(-)gammadelta(+) T cells infiltrating liver allografts produce Th2-type cytokines and are associated with immunologic unresponsiveness induced by DST.

Acute Disease↗

PubMed2001

High prevalence of vitamin D deficiency in Japanese female patients with Graves' disease.

We reported previously that vitamin D deficiency is a causal mechanism of postoperative tetany in patients with Graves' disease. The aim of the present study was to determine the prevalence of vitamin D deficiency by reviewing serum 25(OH)D levels in 208 patients with Graves' disease (146 women, 62 men) during a 1 year period. Serum 25(OH)D levels were significantly lower (p < 0.001) in female Graves' patients (31.8 +/- 13.3 nmol/l) than in male patients (41.3 +/- 15.0 nmol/l). Vitamin D deficiency (defined as a serum 25(OH)D value below 25 nmol/l) was found in 40% of female patients and in 18% of male patients (p < 0.005). There was a significant seasonal variation in the 25(OH)D concentrations in female patients [amplitude 6.38 (95% CI, 5.42-7.56)], with values below 25 nmol/l found in 58% of female patients during the winter months. There were significant (p < 0.001) differences in serum 25(OH)D levels between age groups in the female patients. The concentrations were lowest in patients in their twenties (25.1 +/- 8.2 nmol/l) and highest in patients in their fifties and sixties (43.2 +/- 13.7 nmol/l). Serum 25(OH)D concentrations might be monitored in patients with Graves' disease during antithyroid drug therapy, and vitamin D and/or calcium supplements are recommended for patients with vitamin D deficiency.

Adolescent↗

PubMed2000

Posttransplant infusion of donor-specific blood induces immunological unresponsiveness in rat hepatic allografts.

BACKGROUND: We previously reported that pretransplant donor-specific blood transfusion (DST) induces CD45RC-CD4+ T cells, Th2-like effector cells, and prolongs rat hepatic allograft survival. Our study investigated the effects of posttransplant DST on rat hepatic allograft survival. METHODS: Three days after transplantation, LEW (RT1(1)) recipient rats with ACI (RT1a) livers were injected i.v. with freshly heparinized donor-specific blood. The time kinetics of CD45RC-CD4+ and CD45RC+CD4+ T cell subsets in hepatic infiltrates were examined. RESULTS: Posttransplant DST significantly prolonged rat hepatic allograft survival. Interferon (IFN)-gamma, interleukin (IL)-12, and IL-18 mRNA levels in hepatic allografts of untreated recipients were significantly greater than in recipients treated with posttransplant DST. However, hepatic allografts of recipients treated with posttransplant DST showed significantly higher IL-4, IL-10, and transforming growth factor (TGF)-beta mRNA levels than untreated recipients. The ratio of CD45RC-CD4+ T cells to CD45RC+CD4+ T cells was significantly higher in hepatic allografts treated with posttransplant DST than in untreated animals. Immunostaining with anti-rat dendritic cell (OX-62) monoclonal antibody revealed that OX-62+ cells were distributed to the splenic red pulp of animals treated with posttransplant DST and to the splenic white pulp in untreated animals. Most OX62+ cells isolated from the spleen of recipients treated with posttransplant DST expressed donor RT1Ba class II major histocompatibility complex antigens, suggesting that OX-62+ cells were of donor origin. CONCLUSION: Posttransplant DST was associated with persistent infiltration of CD45RC-CD4+ T cells, Th2-like effector cells, in rat hepatic allografts, causing immunologic unresponsiveness and establishment of microchimerism in the spleen.

Animals↗

PubMed2000

Screening of the Men1 gene and discovery of germ-line and somatic mutations in apparently sporadic parathyroid tumors.

Hyperparathyroidism is the first manifestation in a majority of multiple endocrine neoplasia (MEN1) patients. To discriminate between sporadic and hereditary parathyroid tumors and characterize MEN1 somatic mutations, we examined MEN1 gene mutations in patients who had undergone surgery for sporadic parathyroid tumors. DNA was extracted from fresh frozen parathyroid tumor specimens from 112 patients as well as from peripheral blood leukocytes from 64 of the 112 patients. Sequence analysis was performed to examine exons 2-10 of the MEN1 gene for mutations. Loss of heterozygosity (LOH) was also examined by an analysis of codon 418 and 541, which lie within a polymorphic region of MEN1. Somatic MEN1 mutations were found in 25 of the 112 patients (22%). Two patients had two point mutations (508del33 and Y341X and 363insT and 1767delT, respectively). A total of 27 mutations were characterized, 20 of which have not been reported previously. There were 7 nonsense mutations, 10 frameshift mutations, 2 splice site deletions, 5 missense mutations, and 3 in-frame mutations. Nineteen mutations (70%) predicted truncation of the menin protein. Germ-line MEN1 mutations were found in 3 of 64 patients (5%) who had no family history of endocrine tumors associated with MEN1, and these patients were identified as MEN1 gene probands. LOH at the MEN1 locus was detected in three parathyroid tumors showing germ-line mutation. LOH was significantly frequent in parathyroid tumors with somatic MEN1 mutations (15 of 22 tumors, 68%) but not in those without germ-line or somatic MEN1 mutations (14 of 51 tumors, 28%; P = 0.0011). Our findings suggest that alterations of both alleles of the MEN1 gene may be associated not only with endocrine tumors of affected MEN1 patients but also with sporadic parathyroid tumors. Germ-line MEN1 gene analysis can distinguish heritable from nonheritable parathyroid tumors, and MEN1 gene evaluation of patients with apparently sporadic parathyroid tumor is recommended before parathyroid surgery.

Adult↗

PubMed2000

Evaluation and comparison of ion permeation and agonist selectivities for N-methyl-d-aspartate receptor channels with different subunit compositions in bilayer lipid membranes based on integrated single-channel currents.

To quantify the ion-permeation ability of the recombinant epsilon1-4/zeta1 channel activated by agonists, the magnitude of agonist-induced integrated single-channel currents for the epsilon2-4/zeta1 N-methyl-d-aspartate (NMDA) channels in bilayer lipid membranes (BLMs) was evaluated electrochemically based on the single-channel recordings. The recombinant epsilon2-4/zeta1 channels were purified from Chinese hamster ovary cells expressing each channel and incorporated in BLMs formed by the tip-dip method. Three typical agonists, l-glutamate, NMDA, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (l-CCG-IV), were investigated at a concentration of 50 microM. The magnitude of l-glutamate-induced integrated current was found to depend on the epsilon-subunit composition and to increase in the order of epsilon2/zeta1 > epsilon1/zeta1 approximately epsilon4/zeta1 > epsilon3/zeta1, which differs from that of the reported binding affinities (EC(50)) between l-glutamate and each channel type. On the other hand, the magnitude of the integrated currents induced by NMDA and l-CCG-IV did not vary among the four channel types. The order of agonist selectivity toward the epsilon2-4/zeta1 channels in terms of the magnitude of the integrated current was l-glutamate > l-CCG-IV approximately NMDA for the epsilon2/zeta1 channel, l-CCG-IV > NMDA > l-glutamate for the epsilon3/zeta1 channel, and l-CCG-IV approximately l-glutamate > NMDA for the epsilon4/zeta1 channel, suggesting that the agonist selectivity also depends on the epsilon-subunit composition. The present study shows that each epsilon1-4/zeta1 channel has its own ability of ion permeation, i.e., its own signal transduction ability, which is not parallel to its binding ability.

Animals↗

PubMed2000

Manganese deposition in the globus pallidus in patients with biliary atresia.

BACKGROUND: Chronic liver diseases may alter trace element contents in the brain. Among these trace elements, manganese is a ubiquitous transition metal excreted by the liver into the bile. Blood concentrations of manganese are elevated in patients with biliary atresia who have undergone hepatic portoenterostomy. The present study investigated the effects of liver transplantation on manganese deposition in the brain in such patients. METHODS: The signal intensity of the globus pallidus was calculated as an index defined as the percentile ratio of signal intensity in the globus pallidus to the subcortical frontal white-matter in sagittal T1-weighted magnetic resonance imaging planes. RESULTS: Brain magnetic resonance imaging revealed hyperintense signals in the globus pallidus due to manganese deposition in biliary atresia patients. Few neurologic symptoms related to manganese intoxication were observed. However, one 23-year-old female with biliary atresia had depressive symptoms and dyskinesia; she improved after oral administration of the dopamine precursor, L-DOPA. Manganese deposition disappeared in two patients after living-related reduced-size hepatic transplantation. CONCLUSIONS: Manganese accumulates in the brain during cholestasis associated with biliary atresia and disappears after hepatic transplantation. Manganese deposition is likely to be subclinical and reversible but may be associated with some age-related neurologic symptoms.

Adult↗

PubMed2000

Effects of neurosteroids on Ca(2+) signaling mediated by recombinant N-methyl-D-aspartate receptor expressed in Chinese hamster ovary cells.

Pregnenolone sulfate (PREGS) potentiates the N-methyl-D-aspartate (NMDA) receptor-mediated Ca(2+)-signals in cultured hippocampal neurons. The NMDA receptor family has several different subunits whose expression in neurons has distinct spatial and temporal patterns. To examine subunit specificity of the PREGS action, we have investigated the effect of PREGS on recombinant GluR epsilon2/zeta1 (NR2B/NR1) type NMDA receptors stabley expressed in Chinese hamster ovary cells using heat shock promoters. PREGS enhanced the Ca(2+) influx through the GluR epsilon2/zeta1 receptors in a dose-dependent manner. The EC(50) of PREGS for the GluR epsilon2/zeta1 receptors was 8.6 microM. Other sulfated neurosteroids, dehydroepiandrosterone sulfate (DHEAS), 17beta-estradiol sulfate and 3alpha-ol-5beta-pregnan-20-one sulfate (3alpha5betaS), inhibited the positive modulatory effect of PREGS on the GluR epsilon2/zeta1 NMDA receptors. Ifenprodil, a specific inhibitor of GluR epsilon2 subunit, abolished the NMDA-induced Ca(2+) influx even in the presence of PREGS. These results imply that PREGS positively modulates the Ca(2+) influx through the GluR epsilon2/zeta1 receptors which are expressed from the embryonic period.

Action Potentials↗

PubMed2000

Indications for bilateral modified radical neck dissection in patients with papillary carcinoma of the thyroid.

HYPOTHESES: After subtotal thyroidectomy with modified radical neck dissection of the affected side, nodal recurrence at the contralateral cervical side indicates a poor prognosis for patients with papillary thyroid cancer. Bilateral modified radical neck dissection is beneficial for patients at high risk for contralateral nodal recurrence. DESIGN AND SETTING: Retrospective study of patients with papillary cancer who were treated surgically from January 1, 1970, through December 31, 1995, at the Noguchi Thyroid Clinic and Hospital Foundation, Beppu, Japan. PATIENTS: Patients (N = 1776) had primary tumors greater than 10 mm in maximum diameter and underwent thyroidectomy and ipsilateral modified radical neck dissection with curative intent. RESULTS: Thirty-two patients (1.8%) developed contralateral lymph node metastases during the mean follow-up period of 12.1 years. The risk factors for contralateral nodal recurrence were male sex, large primary tumor, tumor extension over the isthmus, extracapsular adhesion or invasion to surrounding tissues, and the presence of gross nodal metastasis at initial surgery. These patients had a greater number of distant metastases (31.1% vs 0.7%; P<.001) and a lower 10-year survival rate (83.7% vs 99.3%; P<.001) than patients without nodal recurrence. CONCLUSION: Bilateral modified radical neck dissection should be considered for patients with papillary carcinoma who show risk factors for contralateral nodal recurrence, as it could prevent a second operation and may improve their outcome.

Adult↗

PubMed2000

Thrombin and factor Xa enhance neutrophil chemoattractant production after ischemia/reperfusion in the rat liver.

BACKGROUND: Clotting proteases may affect leukocyte effector function. Activation of the coagulation cascade after ischemia/reperfusion stimulates cytokine production by activated macrophages. Cytokine-induced neutrophil chemoattractant (CINC) may also be important in the pathophysiology of liver ischemia/reperfusion injury. We investigated the effects of a selective factor Xa inhibitor, DX-9065a, on CINC expression after ischemia/reperfusion in the rat liver. METHODS: Liver ischemia was induced in rats by occluding the portal vein for 30 min. DX-9065a (9 mg/kg) was injected intravenously 5 min before vascular clamping. Serum CINC concentrations were measured by enzyme-linked immunosorbent assay. Levels of CINC mRNA in the liver were determined by Northern blot analysis. We also examined in vitro CINC production by peritoneal macrophages in response to alpha-thrombin or factor Xa. RESULTS: Serum CINC concentrations increased and peaked 6 h after reperfusion. However, pretreatment of animals with DX-9065a resulted in significantly smaller increases in CINC after reperfusion. Pretreatment with DX-9065a also significantly reduced CINC mRNA levels in the liver after ischemia/reperfusion. In vitro CINC production by peritoneal macrophages was enhanced by alpha-thrombin, as well as factor Xa. CONCLUSIONS: Thrombin and factor Xa stimulate CINC production by macrophages. A selective inhibitor of factor Xa, DX-9065a, attenuates neutrophil chemoattractant production after ischemia/reperfusion injury of the rat liver.

Animals↗

PubMed2000

Urinary trypsin inhibitor reduces C-X-C chemokine production in rat liver ischemia/reperfusion.

BACKGROUND AND AIM: Protease inhibitors attenuate ischemia/reperfusion injury. However, the underlying mechanisms by which protease inhibitors prevent reperfusion injury remain obscure. Neutrophils play an important role in reperfusion injury. We studied the effects of urinary trypsin inhibitor (UTI) on production of the C-X-C chemokine, cytokine-induced neutrophil chemoattractant (CINC), by Kupffer cells during ischemia/reperfusion of the liver. METHODS: Liver ischemia was induced in rats by occlusion of the portal vein for 30 min. UTI (50,000 U/kg) was injected intravenously 5 min before vascular clamping. Serum CINC concentrations were measured by enzyme-linked immunosorbent assay. Levels of CINC mRNA in the liver were determined by Northern blot analysis. We also examined the inhibitory effects of UTI on in vitro CINC production by peritoneal macrophages in response to neutrophil elastase (NE). RESULTS: Serum CINC concentrations increased and peaked 6 h after reperfusion. However, pretreatment of animals with UTI blunted this increase in CINC and significantly reduced CINC mRNA levels in the liver after ischemia/reperfusion. UTI also decreased neutrophil accumulation in the liver 24 h after reperfusion. In vitro CINC production by Kupffer cells from rats pretreated with UTI 3 h after ischemia/reperfusion was significantly decreased compared to those from untreated animals. UTI reduced NE activity in vitro in a dose-dependent manner, and UTI significantly reduced in vitro CINC production by peritoneal macrophages stimulated with NE. CONCLUSION: UTI reduces the production of CINC by Kupffer cells stimulated with NE, attenuating ischemia/reperfusion injury of the liver.

Alanine Transaminase↗

PubMed2000

Manganese deposits in patients with biliary atresia after hepatic porto-enterostomy.

PURPOSE: The aim of this study was to determine if there is latent manganese toxicity in patients with biliary atresia. METHODS: Fifteen children with biliary atresia were examined postoperatively with regard to whole-blood manganese levels using brain magnetic resonance imaging (MRI) and I-123 iodoamphetamine (IMP) per rectal portal scintigraphy. RESULTS: Nine (60%) of the 15 had high whole-blood manganese levels (mean, 4.1 microg/dL; range, 1.2 to 9.6; normal, 0.5 to 2.5), and these 9 had hyperintense globus pallidus on T1-weighted images, with no corresponding signal change in T2 sequences. I-123 IMP per rectal portal scintigraphy was done for 13 patients to evaluate portosystemic shunt flow. 12 (92%) of these patients had an increased flow. Mean shunt ratio was estimated to be 41% (range, 0.6 to 98; normal, <5%). Encephalopathy was evident in only 1 patient. CONCLUSIONS: Some patients with biliary atresia in the postoperative period have manganese deposits in globus pallidus on T1-weighted images and high whole-blood manganese levels, possibly caused by increased portsystemic shunt, and a latent or subclinical encephalopathy is also present.

Adolescent↗