[A case of chronic progressive neuro-Behçet disease with extensive cerebral atrophy and elevated CSF IL-6 activity treated with infliximab]

A 43-year-old man without a previous episode of uveitis presented with slowly progressive neurological symptoms that appeared within the past year such as dysarthria, ataxic gait, and behavioral changes. Brain MRI findings showed atrophic lesions in the brainstem and cerebellum. Because these clinical symptoms and abnormal MRI findings indicated spinocerebellar degeneration as the initial diagnosis, he was admitted to our hospital. On admission, we noticed that he had non-neurological manifestations of Behçet disease, such as stomatitis, genital ulcers, and folliculitis. HLA-B51 was positive. He also showed pleocytosis (29 cells/mm³, predominantly mononuclear cells) and elevated cerebrospinal fluid (CSF) IL-6 levels (213 pg/ml), hence he was diagnosed with chronic progressive neuro-Behçet disease (CPNBD). The therapeutic effect of a high-dose intravenous methylprednisolone pulse (1,000 mg/day for 3 days) and methotrexate (maximum dosage, 16 mg/week) was poor against both neurological symptoms and CSF findings. Intravenous infliximab therapy (5 mg/kg, 2 weeks) dramatically decreased CSF IL-6 levels (13 pg/ml) but clinical symptoms remained unchanged. MRI findings of extensive cerebral atrophy and increased CSF IL-6 levels at the pretreatment time point reflected irreversible neurological involvement in CPNBD. For cases with progressive psychiatric symptoms and cerebellar ataxia in the early stage of the disease, skin manifestations should be examined immediately, CSF IL-6 levels measured, and immunosuppressive therapy initiated before CPNBD progresses to brainstem atrophy.

Carotid ultrasound features of anomalous left vertebral artery originating from the aortic arch proximal to the left subclavian artery

We present three cases of anomalous origin of the left vertebral artery (LVA) detected during the evaluation of stroke. The VA usually enters the transverse foramen of the sixth cervical vertebra (C6), but an anomalous LVA originating from the aorta frequently enters at a higher level. In our series, ultrasound of the LVA showed entry at C4 in two patients and at C5 in one patient. These findings suggested anomalous LVA origin, and three-dimensional computed tomography demonstrated the LVA arising from the aorta proximal to the left subclavian arteries. Carotid duplex ultrasound is useful for the diagnosis of this anomaly.

[Efficacy of potassium bromide in the treatment of drug-resistant epilepsy: a case of new-onset refractory status epilepticus]

A 40-year-old man presented with a series of generalized tonic-clonic seizures after febrile illness. He developed status epilepticus and required mechanical ventilation with anesthetics. Steroid pulse, intravenous immunoglobulin, and immunoadsorption therapy were administrated, and the status epilepticus improved; however, drug-resistant seizures remained. Despite the use of several antiepileptic drugs, seizures frequently occurred. Additional administration of potassium bromide resulted in significant suppression of seizures. Potassium bromide is regarded as an effective medication for pediatric refractory epilepsy after encephalitis. The present case is considered to be new-onset refractory status epilepticus (NORSE) syndrome based on clinical features, and potassium bromide could be effective in treating adult refractory epilepsy, such as NORSE syndrome.

Biliverdin protects against the deterioration of glucose tolerance in db/db mice

AIMS/HYPOTHESIS

We have previously shown a negative correlation between serum bilirubin levels and prevalence of type 2 diabetes, suggesting that bilirubin inhibits development of this disease. To confirm this hypothesis, we investigated whether administration of biliverdin, the precursor of bilirubin, protects against the deterioration of glucose tolerance in db/db mice, a rodent model of type 2 diabetes.

METHODS

Biliverdin (20 mg/kg daily) was orally administered to 5-week-old db/db mice for 4 weeks. After 4 weeks of treatment, i.p. glucose tolerance and insulin tolerance tests were performed. Insulin content was evaluated by immunostaining and ELISA. Oxidative stress markers (8-hydroxy-2'-deoxyguansosine and dihydroethidium staining) and expression of NADPH oxidase components Pdx1 and Bax were also evaluated in isolated islets.

RESULTS

Treatment with biliverdin partially prevented worsening of hyperglycaemia and glucose intolerance in db/db mice. This effect was accompanied by a significant increase in insulin content and Pdx1 expression, and a significant decrease of apoptosis and Bax expression in pancreatic islets from db/db mice. At the same time, levels of oxidative stress markers and NADPH oxidase component production in islets were normalised. Biliverdin had little effect on HOMA of insulin resistance or insulin resistance evaluated by insulin tolerance tests.

CONCLUSIONS/INTERPRETATION

Biliverdin may protect against progressive worsening of glucose tolerance in db/db mice, mainly via inhibition of oxidative stress-induced beta cell damage.

Lens exposure during brain scans using multidetector row CT scanners: methods for estimation of lens dose

BACKGROUND AND PURPOSE

Some recent studies on radiation lens injuries have indicated much lower dose thresholds than specified by the current radiation protection guidelines. The purpose of this research was to measure the lens dose during brain CT scans with multidetector row CT and to assess methods for estimating the lens dose.

MATERIALS AND METHODS

With 8 types of multidetector row CT scanners, both axial and helical scans were obtained for the head part of a human-shaped phantom by using normal clinical settings with the orbitomeatal line as the baseline. We measured the doses on both eyelids by using an RPLGD during whole-brain scans including the orbit with the starting point at the level of the inferior orbital rim. To assess the effect of the starting points on the lens doses, we measured the lens doses by using 2 other starting points for scanning (the orbitomeatal line and the superior orbital rim).

RESULTS

The CTDIvols and the lens doses during whole-brain CT including the orbit were 50.9-113.3 mGy and 42.6-103.5 mGy, respectively. The ratios of lens dose to CTDIvol were 80.6%-103.4%. The lens doses decreased as the starting points were set more superiorly. The lens doses during scans from the superior orbital rim were 11.8%-20.9% of the doses during the scans from the inferior orbital rim.

CONCLUSIONS

CTDIvol can be used to estimate the lens dose during whole-brain CT when the orbit is included in the scanning range.

Role of E-cadherin Molecules in Spheroid Formation of Hepatocytes Adhered on Galactose-Carrying Polymer as an Artificial Asialoglycoprotein Model

The role of E-cadherin in the spheroid formation of hepatocytes adhered on the poly(N-p-vinylbenzyl-D-lactonamide) (PVLA) as a model ligand for asialoglycoprotein receptors (ASGP-R) of hepatocytes was studied. Expression of E-cadherin was increased in round hepatocytes adhered on a high-coating density of PVLA (100 microg/ml), and also in flat ones adhered on a low-coating density of PVLA (1 microg/ml) in the presence of epidermal growth factor (EGF). Hepatocyte spheroids formed on the high-coating density of PVLA in the presence of EGF after 48 h were inhibited by an anti-E-cadherin monoclonal antibody (ECCD-1). From immunofluorescence and confocal laser microscopy, E-cadherin was localized in the intercellular boundaries and concentrated at the inside surface of aggregated cells. As a result, E-cadherin could play an important role in hepatocyte assembly.

Adsorption behaviors of poly(N-p-vinylbenzyl-4-o-β-d-galactopyranosyl-[1→4]-d-gluconamide) by quartz-crystal microbalance

Adsorption behaviors of amphiphilic poly(N-p-vinylbenzyl-4-o-beta-d-galactopyranosyl-[1-->4]-d-gluconamide) (PVLA) on the polystyrene (PS) surface was studied using 27 MHz quartz-crystal microbalance (QCM). The amount of adsorbed PVLA on PS surface was increased with an increase of PVLA concentration as a Langmuir-type in a monolayer. The saturated mass change (DeltaM(max)) and association constant (K(a)) of PVLA on PS surface were 498.6 ng/cm(2) and 1.93 x 10(7)M(-1), respectively. The adsorbed PVLA on PS surface was specifically recognized by Allo A lectin due to specific interaction between galactose moieties in the PVLA and Allo A. The hydrophobic interaction between hydrophobic main chain of PVLA and hydrophobic surface of PS was reduced in the presence of urea and the diameter of PVLA aqueous solution was decreased with an increase of urea concentration.

Isolated dissection of the superior mesenteric artery: CT findings in six cases

Dissection of the superior mesenteric artery (SMA) not associated with aortic dissection is rare. The purpose of this study is to describe the computed tomographic (CT) findings of this condition. We studied the CT findings of six patients with isolated dissection of the SMA. CT demonstrated thrombosis of the false lumen or intramural hematoma (n = 4) and/or intimal flap (n = 4) in all six patients. Other CT findings were enlarged diameter of the SMA (n = 5), increased attenuation of the fat around the SMA (n = 5), and hematoma in the mesentery with hemorrhagic ascites (n = 1). CT is useful for the diagnosis of isolated dissection of the SMA, and increased attenuation of the fat around the artery is considered the key to the diagnosis when no definite findings are evident.

Enhanced effect of sulfonylurea (SU) in copolymer comprising a sugar moiety and SU derivative as double ligands on insulin secretion from MIN6 cells

Copolymers composed of sulfonylurea (SU) as an antagonist of ATP-sensitive K+ channel and sugar moieties as double ligands were synthesized. Insulin secretion from MIN6 cells (insulinoma cell line) in contact with the copolymers was evaluated. MIN6 cells attached to the poly(N-p-vinylbenzyl-D-maltonamide-co-SU) [P(VMA-co-SU)]-coated dishes were in the more aggregated form as compared to other polymer-coated surfaces. By introducing SU into the sugar bearing homopolymer, an enhanced effect on insulin secretion from MIN6 cells was observed due to the specific interaction between SU ligands and SU receptors on the beta-cell membrane. P(VMA-co-SU) composed of SU and non-reducing glucose moieties demonstrated enhanced insulin secretion from MIN6 cells and faster proliferation of MIN6 cells as compared to poly(N-p-vinylbenzyl-D-lactonamide-co-SU) [P(VLA-co-SU)] probably owing to the glucose transporters presence on the MIN6 cell membrane. Insulin secretion from MIN6 cells pretreated with diazoxide as an agonist of ATP-sensitive K+ channel was suppressed.

Changes in plasma adenosine concentrations during normal pregnancy

The aim of this study was to measure changes in plasma adenosine concentration [ADO] during a normal pregnancy and to evaluate the possible role of platelets and red blood cells (RBC) as causes of changes in plasma [ADO]. We measured the plasma [ADO] in normal pregnant women (n = 11) during the first, second and third trimesters. The mean plasma [ADO] in the third trimester was 0.41 +/- 0.08 microM (means +/- SEM), significantly higher than in the first and second trimesters (p < 0.05). In pregnant women, platelet and RBC counts, hematocrit and hemoglobin concentration decreased slightly throughout the pregnancy. The elevation in the plasma [ADO] correlated inversely with the platelet count (r = -0.43, p < 0.05). These results suggest that an increase in the plasma [ADO] in the third trimester may be attributed to the enhanced adenosine release from activated platelets.

Receptor-mediated cell modulator delivery to hepatocyte using nanoparticles coated with carbohydrate-carrying polymers

Cell modulators such as colchicine (CO), cytochalasin B (CY) and taxol (TX) loaded nanoparticles coated with carbohydrate-carrying polymers, as hepatocyte-specific targeting material using galactose ligands as recognition signals to asialoglycoprotein receptors were prepared by the diafiltration method. Effects of cell modulators from their loaded nanoparticles on morphology of hepatocytes were studied. Receptor-mediated endocytosis of the nanoparticles were examined by fluorescence and confocal laser microscopy. It was found that the shapes of most hepatocytes were changed for the CY-loaded, TX-loaded, or CO-loaded nanoparticles whereas their shapes were not changed in comparison with control when CY, TX, or CO were mixed with the nanoparticles. From the fluorescence and confocal laser microscopic studies, it is suggested that the nanoparticles coated with sugar-carrying polymers were internalized by the hepatocytes through the receptor-mediated mechanism.

First presentation of polymyositis postpartum following intrauterine fetal death

We present a case of polymyositis (PM) following intrauterine fetal death. The first presentation of PM in the patient was during postpartum. The patient was referred to our hospital because of a fever of unknown cause 13 d after delivery of dead fetus at 32 weeks' gestation. PM was diagnosed based on the increased serum creatine phosphokinase level, typical electromyogram findings and characteristic muscle biopsy findings.

B-cell-type malignant lymphoma with placental involvement

We present here a case of B-cell-type mediastinal malignant lymphoma during pregnancy complicated by placental involvement. In this case, some nodular high-echo patterns were recognized in the placenta by ultrasonography. A cesarean section and resection of the mediastinal tumor were performed at 33 weeks and 6 days of gestation due to the deterioration of the dyspnea. A female infant weighing 1,868 g was delivered and she is now a healthy 2-year-old. The mother, however, died of the disease 1 month after surgery, due to progression of the tumor. The placenta showed numerous white firm nodules varying from 3 mm to 3 cm in diameter. The pathologic findings of both the mediastinal tumor and the placenta indicated primary mediastinal (thymic) B-cell lymphoma.

Purification and properties of extracellular carboxyl proteases of acid-tolerant bacteria, isolated from compost

Four strains of acid-tolerant and protein-using bacteria were isolated from compost. Two of them, Gram-negative strains MB8 and MB11, were identified as a new genus close to Stenotrophomonas species MB8 and Burkholderia species MB11, respectively. Both bacteria produced extracellular carboxyl proteases (CP) in acid-casein-starch medium. The enzymes, termed CP MB8 and CP MB11, purified through ion exchange and gel filtration chromatographies had molecular weights of 61,000 (CP MB8) and 36,000 (CP MB11) as estimated by SDS-PAGE, and showed optimum activities with hemoglobin as a substrate at pH 3.5 (CP MB8) and pH 3.7 (CP MB11) at 55 degrees C. Both of the enzymes were not inhibited by pepstatin, DAN, or EPNP. These results suggest that both enzymes are members of the pepstatin-insensitive carboxyl proteinase family (EC 3.4.23.33), except for a larger molecular weight of the CP MB8 enzyme.

Transcatheter embolization of arteriovenous malformations in Cowden disease

A patient with Cowden disease and multiple arteriovenous malformations (AVMs) that resulted in high output heart failure is described. Cowden disease is a familial syndrome characterized by endodermal, mesodermal and ectodermal dysplasia causing benign and malignant tumors of the skin, breast, gastrointestinal tract, and thyroid gland. Our patient had gastrointestinal polyposis, a right renal tumor, a left lung tumor, an adenomatous goiter, and typical dermatologic findings such as facial papules, acral keratosis, gingival papillomatosis and hemangiomas. AVMs were observed in the pelvis, cervical vertebra, liver, and right supraclavicular area. Transcatheter embolization was performed 7 times for the pelvic AVMs, but the effect decreased with repetition and the patient died of heart failure 2 years after the first embolization. The serum levels of tissue plasminogen activator (t-PA), platelet-derived growth factor (PDGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), and transforming growth factor beta1 were high, suggesting that these angiogenic molecules may play a role in the pathogenesis of AVMs in Cowden disease.

Naftopidil, a novel alpha1-adrenoceptor antagonist, displays selective inhibition of canine prostatic pressure and high affinity binding to cloned human alpha1-adrenoceptors

The pharmacological profiles of the alpha1-adrenoceptor antagonists naftopidil, tamsulosin and prazosin were studied in an anesthetized dog model that allowed the simultaneous assessment of their antagonist potency against phenylephrine-mediated increases in prostatic pressure and mean blood pressure. The intravenous administration of each of these compounds dose-dependently inhibited phenylephrine-induced increases in prostatic pressure and mean blood pressure. To further assess the ability of the three compounds to inhibit phenylephrine-induced responses, the doses required to produce a 50% inhibition of the phenylephrine-induced increases in prostatic and mean blood pressure and the selectivity index obtained from the ratio of those two doses were determined for each test compound. Forty minutes after the intravenous administration of naftopidil, the selectivity index was 3.76, and those of tamsulosin and prazosin were 1.23 and 0.61, respectively. These findings demonstrated that naftopidil selectively inhibited the phenylephrine-induced increase in prostatic pressure compared with mean blood pressure in the anesthetized dog model. The selectivity of naftopidil for prostatic pressure was the most potent among the test compounds. In addition, using cloned human alpha1-adrenoceptor subtypes, naftopidil was selective for the alpha1d-adrenoceptor with approximately 3- and 17-fold higher affinity than for the alpha1a- and alpha1b-adrenoceptor subtypes, respectively. The selectivity of naftopidil for prostatic pressure may be attributable to its high binding affinity for alpha1a- and alpha1d-adrenoceptor subtypes.

Inhibition of HIV-1 Nef-induced apoptosis of uninfected human blood cells by serine/threonine protein kinase inhibitors, fasudil hydrochloride and M3

The Nef protein of HIV-1 binds to and induces apoptotic cytolysis of uninfected but activated human peripheral blood mononuclear cells (PBMC) and various cell line cells derived from CD4+ T, CD8+ T and B lymphocytes, macrophages, and neutrophils. The Nef-induced apoptosis also occurs with blood cells not expressing CD95 (Fas). The Nef-induced apoptosis as well as Fas-mediated apoptosis was inhibited by acetyl-Try-Val-Ala-Asp-CHO, an IL-1beta converting enzyme (ICE) inhibitor. On the other hand, serine/threonine protein kinase (PK) inhibitors, H-7, fasudil hydrochloride and M3, inhibited the Nef-induced apoptosis, and not the Fas-mediated one, without affecting the cell-binding activity of Nef and Nef-binding capacity of the activated cells. Preincubation of the cells with the drugs before being bound by Nef was required for the inhibition of apoptosis. These results suggest that the PK inhibitors specifically act on a cellular protein involved in the upper stream of signal transduction pathway of the Nef-induced apoptosis, which is different from the Fas-mediated pathway but meets it upstream of ICE. In addition, the drugs suppressed the cellular activation-associated cell surface expression of a putative Nef-binding protein in PBMC, although they had no influence on its expression in cell line cells. These findings suggest the feasibility of clinical use of the PK inhibitors to prevent the development of AIDS by inhibiting the Nef-induced apoptosis of uninfected blood cells.

Nef protein of HIV-1 induces apoptotic cytolysis of murine lymphoid cells independently of CD95 (Fas) and its suppression by serine/threonine protein kinase inhibitors

The Nef protein of HIV-1 is suggested to play a role in depletion of uninfected CD4+ T cells leading to the development of AIDS. The recombinant soluble Nef protein was shown to bind to cell surfaces of various murine lymphoid cell lines, including T and B lymphocytes, mastocytoma cells and macrophages. Cross-linking of the cell-bound Nef protein with anti-Nef antibodies induced apoptotic cytolysis of the cells. Although primary lymphocytes from young mice resisted Nef binding and Nef-induced cytolysis, treatment of the cells with concanavalin A or phytohemagglutinin made them susceptible to these activities, indicating that cellular activation is required for the apoptosis. The Nef-induced apoptosis also occurred with murine cells not expressing CD95 (Fas). These findings were quite similar to those obtained for human blood cells, suggesting that the mouse is applicable for analysis of Nef activities. The Nef-induced apoptosis was efficiently suppressed by serine/threonine protein kinase inhibitors, H7, fasudil hydrochloride and M3, which did not inhibit CD95 (Fas)-mediated apoptosis. On the other hand, bisindolylmaleimide, a protein kinase C inhibitor which inhibits CD95 (Fas)-mediated apoptosis, did not affect Nef-induced apoptosis. These results suggest that the Nef-induced apoptosis of murine cells involved a serine/threonine protein kinase-dependent signal transduction pathway distinct from the CD95 (Fas)-mediated system.

HIV-1 Nef protein-induced apoptotic cytolysis of a broad spectrum of uninfected human blood cells independently of CD95(Fas)

The Nef protein of HIV-1 binds to uninfected CD4+T lymphocytes and induces apoptotic cytolysis of the cells. We examined several human blood cell lines and peripheral blood mononuclear cells (PBMCs) for Nef-induced apoptotic cell death. Soluble Nef protein was shown to bind to the cell surface of not only CD4+T cells but also CD8+T lymphocytes, B lymphocytes, macrophages and neutrophils. PBMCs from normal subjects resisted Nef binding, and activation of the cells with phytohemagglutinin or concanavalin A converted the cells to be susceptible to the binding. Cross-linking of the Nef proteins bound to the cell surfaces with anti-Nef antibody-induced apoptotic cytolysis of the cells. The Nef-mediated apoptosis occurred independently of CD95(Fas). These results suggest that soluble Nef protein, which is found in sera of HIV-1 infected patients, is involved in the destruction of a broad spectrum of uninfected blood cells leading to immune suppression.

Specific interaction between erythrocytes and a glucose-carrying polymer mediated by the type-1 glucose transporter (GLUT-1) on the cell membrane

A reducing glucose-carrying polymer, called poly [3-O-(4'-vinylbenzyl)-D-glucose] (PVG), interacted with erythrocytes carrying the type-1 glucose transporter (GLUT-1) on the cell membrane. The cooperative interaction between a number of GLUT-1s and a number of reducing 3-O-methyl-D-glucose moieties on a PVG polymer chain is responsible for the increase in the interaction with erythrocytes. In contrast to the PVG homopolymer, other sugar-carrying polymers showed lower interaction with erythrocytes. The affinity of erythrocytes and PVG was studied using FITC-labeled glycopolymers. The fluorescence intensity significantly changed, whereas a small change in fluorescence intensity was observed for other homopolymers. The specific interaction between GLUT-1 on erythrocytes and the PVG polymer carrying reducing glucose was suppressed by the inhibitors, phloretin, phloridzin, and cytochalasin B, and a monoclonal antibody to GLUT-1. Direct observation by confocal laser microscopy with the use of FITC-labeled PVG demonstrated that erythrocytes interacted with the soluble form of the PVG polymer via GLUT-1, while fluorescence labeling of the cell surface was prevented on pretreatment with the monoclonal antibody to GLUT-1.

Simple preparation of nanoparticles coated with carbohydrate-carrying polymers

Nanoparticles bearing carbohydrate chains on the surface can be prepared by the simple diafiltration method. The nanoparticles prepared by the present method displayed high yield, no-aggregation formation, small size, narrow size distribution, and one-step procedure. Also, the high density carbohydrate chains on the particles can be recognized by liver cells.

Surgical neck fractures of the proximal humerus: a laboratory evaluation of ten fixation techniques

OBJECTIVE

A biomechanical cadaver study was performed to compare the stability and ultimate strength of ten standard fixation techniques used for the treatment of surgical neck fractures of the proximal humerus.

DESIGN

One hundred twenty (60 fresh frozen, 60 embalmed) proximal humerus specimens were selected and divided into two groups: fresh frozen specimens represented a nonosteopenic group and embalmed specimens an osteopenic group. Simulated fractures were created at the level of the surgical neck, reduced, and randomly assigned to one of ten methods of fixation (six fresh frozen and six embalmed specimens per fixation group). These constructs were then mechanically tested with the humeri oriented to create primarily shear loading of the fixation.

RESULTS AND CONCLUSIONS

The T-plate and screws provided significantly stronger fixation (p < 0.005) in the fresh frozen specimens than all other methods. The Ender nails/tension band construct was the second strongest fixation technique, providing significantly stronger fixation (p < 0.01) than all the remaining techniques. Four Schanz pins with one pin placed through the greater tuberosity followed by the T-plate and screws provided the strongest fixation in embalmed specimens. Tension band fixation in both humeral groups was shown to provide the least effective fixation.

Patellofemoral complications following total knee arthroplasty. Correlation with implant design and patient risk factors

Results of 211 total knee arthroplasty operations were retrospectively evaluated to identify patients with knees at greatest risk for the development of patellofemoral complications and to determine the incidence and type of patellofemoral complications associated with different patellar implants. Patellofemoral complications occurred in 27 knees (12.8%). Osteoarthritis and obesity were associated with an increased incidence of patellofemoral problems. Significantly higher rates of patellofemoral complications were noted with metal-backed patellar implants and with patellar components implanted without cement. The loosening rate with cementless fixation was 13.5%. The lowest rate of patellofemoral complications following total knee arthroplasty was obtained with all-polyethylene domed patellar components implanted with cement.

[Experimental study of flow rates in microcatheters using various kinds of contrast materials: comparison of imaging capability by iodine delivery rates]

In order to establish the optimal injection technique for abdominal digital subtraction angiography (DSA), flow rate measurement was performed under various combinations of all the currently available iodinated contrast materials with two types of coaxial microcatheters. In vitro study was done utilizing a plastic model of the abdominal aorta with the tip of the catheter positioned at the presumed proper hepatic artery. A total of 20ml of contrast material was injected by a pressure injector at a rate of 3 ml/sec at 300 or 600 psi, and actual flow volume was measured. Imaging capability was evaluated by calculating iodine delivery rates (IDRs). IDRs were highest in iopamidol 300 mgI/ml and iomeperol 300 mgI/ml, nonionic monomeric contrast materials of medium concentration. The results suggest that the best quality DSA images with injection to the proper hepatic artery using a coaxial microcatheter can be obtained with nonionic monomeric contrast materials of medium concentration.

Antithrombotic effects of recombinant human soluble thrombomodulin (rhs-TM) on arteriovenous shunt thrombosis in rats

We examined the antithrombotic effect of recombinant human soluble thrombomodulin (rhs-TM) using an arteriovenous shunt thrombosis model and its influence on hemostasis in rats. Intravenous administration of rhs-TM (0.5-4 mg/kg) significantly inhibited thrombus formation and prolonged ex vivo activated partial thromboplastin time (APTT) in a dose-dependent manner. Thrombus formation was inhibited to the same extent in animals treated with heparin (25-200 U/kg) and in those treated with rhs-TM (0.5-4 mg/kg), but heparin had a much stronger effect on prolonging APTT. In the hemorrhagic study using the rat template bleeding time method, rhs-TM exhibited the prolongation of the bleeding time only at the highest effective dose (rhs-TM; 4 mg/kg) of the thrombosis experiments. Thus, rhs-TM exhibits the inhibitory effect on thrombus formation with less APTT prolongation in comparison with heparin and without significant pertubation of hemostasis.

Effects of recombinant human soluble thrombomodulin (rhs-TM) on a rat model of disseminated intravascular coagulation with decreased levels of plasma antithrombin III

We reported that recombinant human soluble thrombomodulin (rhs-TM) is effective for disseminated intravascular coagulation (DIC) in vivo, in mice and rats. In the present work, we investigated the effects of decreased plasma antithrombin III (ATIII) levels on anticoagulant effects of rhs-TM, as compared to findings with heparin, of which effect is lowered by the decreased plasma ATIII levels in patients with DIC. Rat plasma ATIII levels decreased when we mixed plasma with anti-rat ATIII antibody and the potential of heparin to prolong APTT or PT was markedly diminished. The potential of rhs-TM to prolong APTT and PT was not affected. In rats injected with anti-rat ATIII antibody, plasma ATIII levels decreased immediately. When the rats were infused with tissue factor (TF), DIC was induced. At doses of rhs-TM and heparin which were equally effective at inhibiting the decrease in platelet count and fibrinogen level in control rats treated with TF, only rhs-TM remained effective in preventing DIC in rats with reduced ATIII levels. Heparin was not effective when administered to these rats with reduced ATIII levels. Therefore, rhs-TM effectively inhibits coagulation independent of ATIII levels, in contrast to heparin, which depends on the ATIII level.

Effects of atrial natriuretic peptide on ischemic brain edema in rats evaluated by proton magnetic resonance method

We examined the effect of atrial natriuretic peptide on cerebral edema in 96 rats. Forty-four rats were given 30 (n = 11), 120 (n = 26), or 150 (n = 7) micrograms/kg of the peptide intravenously over 24 hours after occlusion of the left middle cerebral artery to induce cerebral ischemia. We then measured the brain water content, the brain sodium and potassium contents, the in vitro proton nuclear magnetic resonance longitudinal (T1) and transverse (T2) relaxation times, and the area of the edematous regions. Compared with saline treatment (n = 39), peptide treatment decreased the brain water content in a dose-dependent manner and decreased the brain sodium content significantly (p less than 0.05). Peptide treatment also suppressed the lengthening of both T1 and T2 in edematous tissue (p less than 0.05 and p less than 0.01, respectively) and reduced the area of the edematous regions observed by magnetic resonance imaging (p less than 0.01). Atrial natriuretic peptide appears to have a pharmacological effect on ischemic brain edema, possibly by suppressing the elevation of water content through regulation of electrolyte transport in the brain.

Effects of atrial natriuretic peptide on brain oedema: the change of water, sodium, and potassium contents in the brain

We examined the effect of atrial natriuretic peptide (ANP) administration on cerebral oedema in rats. Intravenous ANP infusion with total dose of 120 micrograms/kg and 100 micrograms/kg suppressed the elevation of water and Na contents in left middle cerebral artery (MCA) occluded and cold injured brain tissue, indicating that ANP has a suppressive effect on cerebral oedema. Similar ANP infusion at a low dose of 1 microgram/kg/h for 6 h also resulted in observation of the anti-oedematous effect in both models, with no observable occurrence of the known systemic effects of ANP on systolic blood pressure (SBP), heart rate (HR), hematocrit, or serum electrolyte ion (Na+, K+, Cl-) concentrations. The results thus suggest that the anti-oedematous effect of ANP is attributable to water and Na content control by ANP specific to the damaged tissue, possibly through inhibition of sodium transport. Taken together with a recent study in which it was shown that ANP might inhibit sodium transport in cerebral microvessel, our results suggest that ANP suppresses the development of brain oedema by inhibiting sodium transport and the coupled water influx.