Pharmacological profile of a new orally active growth hormone secretagogue, SM-130686

SM-130686, an oxindole derivative, is a novel orally active GH secretagogue (GHS) which is structurally distinct from previously reported GHSs such as MK-677, NN703 and hexarelin. SM-130686 stimulates GH release from cultured rat pituitary cells in a dose-dependent manner. Half-maximum stimulation was observed at a concentration of 6.3+/-3.4 nM. SM-130686-induced GH release was inhibited by a GHS antagonist, but not by a GH-releasing hormone antagonist. SM-130686 dose-dependently inhibited the binding of radiolabeled ligand, (35)S-MK-677, to human GHS receptor 1a (IC(50)=1.2 nM). This indicates that SM-130686 stimulates GH release through the GHS receptor. The effect of a single oral administration of SM-130686 on GH release in pentobarbital-anesthetized rats was studied. After treatment with 10 mg/kg SM-130686, plasma GH concentrations measured by radioimmunoassay significantly increased, reaching a peak at 20-45 min, and remained above baseline during the experimental period (60 min). The anabolic effect of repetitive SM-130686 administration was studied in rats. Rats received 10 mg/kg SM-130686 orally twice a day and were weighed every day for 9 days. At day 9 there was a significant increase in both the body weight and the fat free mass (19.5+/-2.1 and 18.1+/-7.5 g respectively). Serum IGF-I concentration was also significantly elevated 6 h after the last dose of SM-130686. An endogenous GHS ligand for the GHS receptor has recently been identified from stomach extract and designated as ghrelin. The GH-releasing activity in vitro relative to ghrelin (100%) was about 52% for SM-130686. It is likely that SM-130686 is a partial agonist for the GHS receptor. In summary, we describe here an orally active GHS, SM-130686, which acts through the GHS receptor. Repetitive administration of SM-130686 to rats, similar to repetitive administration of GH, significantly increased the fat free mass by an amount almost equal to the gain in body weight.

Random amplified polymorphic DNA analysis applied to acute otitis media caused by penicillin non-susceptible Streptococcus pneumoniae

The spread of penicillin non-susceptible Streptococcus pneumoniae (PNSSP) is an emerging problem for the treatment of acute otitis media (AOM). Attendance of children at day care centers, as well as the spread of PNSSP, is a risk factor for AOM. The status of the spread of PNSSP during the acute infection phase of AOM has not been evaluated. We examined the clonality of samples from seven children in a day care center who simultaneously developed AOM caused by PNSSP. The seven isolates from the children, and six control samples were grouped by serotyping, by determining resistance to antimicrobial agents, and by genotyping, carried out by sequencer-based random amplified polymorphic DNA (RAPD), and validated by bootstrap analysis. There was no evidence to indicate the direct dissemination of PNSSP among these patients in the day care center, although the simultaneous occurrence of PNSSP AOM had initially suggested a clonal outbreak. The possible presence of a common ancestral strain suggested the importance of surveillance during the carrier state. The result of RAPD genotyping was highly reproducible, as validated by the high bootstrap score. The use of an automated sequencer, in combination with a careful choice of primers, and commercially established kits, played a significant role in the reproducibility of the studies.

Mutations in the gene encoding c-Abl-binding protein SH3BP2 cause cherubism

Cherubism (MIM 118400) is an autosomal dominant inherited syndrome characterized by excessive bone degradation of the upper and lower jaws followed by development of fibrous tissue masses, which causes a characteristic facial swelling. Here we describe seven mutations in the SH3-binding protein SH3BP2 (MIM 602104) on chromosome 4p16.3 that cause cherubism.

Autosomal dominant craniometaphyseal dysplasia is caused by mutations in the transmembrane protein ANK

Craniometaphyseal dysplasia (CMD) is a rare skeletal disorder characterized by progressive thickening and increased mineral density of craniofacial bones and abnormally developed metaphyses in long bones. Linkage studies mapped the locus for the autosomal dominant form of CMD to an approximately 5-cM interval on chromosome 5p, which is defined by recombinations between loci D5S810 and D5S1954. Mutational analysis of positional candidate genes was performed, and we describe herein three different mutations, in five different families and in isolated cases, in ANK, a multipass transmembrane protein involved in the transport of intracellular pyrophosphate into extracellular matrix. The mutations are two in-frame deletions and one in-frame insertion caused by a splicing defect. All mutations cluster within seven amino acids in one of the six possible cytosolic domains of ANK. These results suggest that the mutated protein has a dominant negative effect on the function of ANK, since reduced levels of pyrophosphate in bone matrix are known to increase mineralization.

Genetic alteration of penicillin non-susceptible Streptococcus pneumoniae observed throughout recurrence of acute otitis media detected by amplified fragment length polymorphism analysis

The prevalence of penicillin non-susceptible Streptococcus pneumoniae (PNSSP) is increasing among isolates from acute otitis media (AOM). Repeated episodes of antibiotic exposure are a well-known risk factor for the isolation of PNSSP although otitis-prone or recurrent AOM cases frequently require repeated courses of antibiotic treatment. In order to evaluate the chronological alteration of S. pneumoniae during recurrences of AOM, strains of S. pneumoniae were isolated from 11 patients, each of whom had experienced 2-4 episodes of AOM, were examined. Every bacterial specimen obtained from a single episode of recurrent AOM was examined by PCR-based penicillin-binding protein (PBP) assay, serotyping, and amplified fragment length polymorphism (AFLP), then compared to other samples from the same case. Two cases (18.2%) showed strain diversity during repeated antibiotic treatments by serotyping or PBP-assay. By AFLP analysis, 6 cases (54.5%) demonstrated heterogeneous strains during recurrent AOM. Clonal survivors of previous episodes of AOM were not always the cause of subsequent episodes of AOM, even in otitis-prone cases.

Measurement of electron beam broadening in stainless steels during EDS analysis in the FEG-TEM

The effect of electron beam broadening on spatial resolution of EDS analysis in a 200 kV cold-FEG-TEM has been investigated for Type 316L stainless steel. Platinum (Pt) was evaporated on half the 316L TEM foil surface, and the difference in Pt concentration profiles obtained by the EDS method from the Pt evaporated surface and its opposite side was analysed as a function of foil thickness. Advantages of Pt use are that Pt is not included in the 316L steel, and it is easily formed as a stable and continuous thin evaporated film on the stainless steel. No change of spatial resolution caused by electron beam broadening was observed in stainless steel foils of less than about 140 nm thick subjected to EDS analysis with the FEG-TEM (incident probe size 1.6 +/- 0.2 nm diameter). Specimens of about 160 nm and more thick had a decrease in spatial resolution, but the decrease was smaller than that predicted from theoretical calculations of beam broadening for stainless steels. It is suggested that only the central part of the broadened electron beam with high intensity influences the spatial resolution of EDS analysis with the FEG-TEM.

Correction of hyperglycaemia reduces insulin resistance and serum soluble E-selectin levels in patients with Type 2 diabetes mellitus

AIMS

To investigate the effects of glycaemic control on insulin sensitivity and serum concentrations of soluble vascular cell adhesion molecule (sVCAM)-1 and E-selectin (sE-selectin) in patients with Type 2 diabetes mellitus. To examine whether reductions in serum adhesion molecule levels correlate with improvement in insulin resistance.

METHODS

A total of 54 patients with Type 2 diabetes were treated for 4 weeks with either diet alone, sulphonylurea or insulin. Fasting glucose, insulin sensitivity, lipids, sVCAM-1, and sE-selectin levels were measured before and after treatment.

RESULTS

All treatment modalities successfully corrected hyperglycemia. Reductions in blood glucose levels resulted in improvement in insulin sensitivity (diet KITT 2.40 +/- 0.26-3.09 +/- 0.36, P < 0.01; sulphonylurea 2.24 +/- 0.16-2.94 +/- 0.18, P < 0.01; insulin 1.68 +/- 0.27-2.16 +/- 0.22%/min, P < 0.05), and decrease in sE-selectin levels (diet 88.4 +/- 14.9-66.2 +/- 10.8, P < 0.05; sulphonylurea 85.1 +/- 11.6-59.8 +/- 7.8, P < 0.01; insulin 84.4 +/- 8.7-66.8 +/- 7.4 ng/ml, P < 0.01), but no change in sVCAM-1 levels. There was a significant correlation between the degree of decrease in sE-selectin levels and improvement in insulin sensitivity (r = -0.38, P < 0.01).

CONCLUSIONS

Correction of hyperglycaemia, independent of treatment modality, resulted in improvement of insulin resistance and decrease in sE-selectin levels. These changes might, in part, contribute to reduce the risk of diabetic microvascular and macrovascular complications in patients with Type 2 diabetes mellitus.

Insulin resistance and coronary risk factors in Japanese type 2 diabetic patients with definite coronary artery disease

Insulin resistance is known as an important risk factor for coronary artery disease (CAD). However, CAD-related mortality in Japanese type 2 diabetics is lower than in Caucasians. To investigate whether insulin resistance is related to CAD in Japanese type 2 diabetics, we measured insulin sensitivity and several coronary risk factors in Japanese patients with type 2 diabetes with and without CAD. Thirty-three patients with definite CAD and 33 age- and sex-matched patients without CAD (control) were studied. Insulin sensitivity was assessed by the K index of insulin tolerance test (KITT). Clinical characteristics, classical risk factors, lipoprotein (a), and insulin sensitivity were compared between the two groups. Patients with CAD had a significantly longer duration of diabetes (9.0 +/- 1.4 vs. 5.5 +/- 0.9 years, P < 0.05, respectively), were mostly hypertensive (69.7 vs. 39.4%, P < 0.05), and more likely to be treated with insulin (45.5 vs. 18.2%, P < 0.05) compared with the control. Concerning the metabolic parameters, patients with CAD had a significantly higher insulin resistance than control (2.40 +/- 0.15 vs. 3.23 +/- 0.17%/min, P < 0.01, respectively), higher triglyceride (1.39 +/- 0.10 vs. 1.05 +/- 0.05 mmol/l, P < 0.05), lower HDL cholesterol (1.05 +/- 0.05 vs. 1.28 +/- 0.06 mmol/l, P < 0.05), and higher lipoprotein (a) (27.5 +/- 4.3 vs. 17.4 +/- 2.0 mg/dl, P < 0.05). Multiple logistic regression analysis indicated that hypertension, insulin resistance, high lipoprotein (a) and triglyceride, and low HDL cholesterol were independently related to CAD. Our results suggest that insulin resistance per se is a significant risk factor for CAD in Japanese patients with type 2 diabetes.

Genomic structures of SCN2A and SCN3A - candidate genes for deafness at the DFNA16 locus

DFNA16 is a form of autosomal dominant non-syndromic hearing loss (ADNSHL) characterized by fluctuating progressive hearing impairment. Earlier, we mapped the deafness-causing gene to chromosome 2q23-24.3. In this paper, we describe fine mapping results using additional markers tightly linked to the DFNA16 candidate region. Critical recombinants at markers D2S354 and D2S124 define a 3.5-cM interval that contains the DFNA16 gene. Positional candidate genes include two members of the voltage-gated sodium channel family, the type 2 alpha subunit (SCN2A) and the type 3 alpha subunit (SCN3A). After showing that SCN2A is expressed in human fetal cochlea, we determined its genomic structure to facilitate mutation screening in our DFNA16 kindred. We also determined the genomic structure of SCN3A. These two genes are oriented head-to-head, with their 5' ends separated by approximately 40 kb; their homology is 82% at the nucleotide level, and 85% for identities and 90% for positives at the amino acid level. They share similar genomic structures and have alternative splice isoforms that are developmentally regulated and highly conserved between species. Although no DFNA16-causing mutations were found in either gene, haplotype analysis with polymorphic markers in SCN2A introns further narrowed the candidate gene interval to the region flanked by D2S354 and STS SHGC-82894.

Effects of nitric oxide on matrix metalloproteinase-2 production by rheumatoid synovial cells

Nitric oxide (NO) is a multifunctional messenger molecule generated from L-arginine by a family of enzymes, including nitric oxide synthase (NOS). This study was performed to examine whether NO modulates the production of matrix metalloproteinases (MMPs), which degrade all components of extracellular matrix (ECM), in rheumatoid synovial cells. We investigated the effects of exogenously generated NO by a NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP), on the MMPs production by rheumatoid synovial cells. Culture media conditioned by SNAP-treated synovial cells were examined by gelatin zymography and immunoblot analysis. Incubation of synovial cells with SNAP resulted in gelatinase A production in a dose-dependent fashion. Furthermore, RT-PCR analysis demonstrated that MMP-2 mRNA expression was induced in SNAP-treated synovial cells. In contrast, SNAP did not influence the production of TIMP-1 and TIMP-2, which preferentially inhibit MMP-2, by rheumatoid synovial cells. Our data indicate that NO could modulate MMP production by rheumatoid synovial cells and therefore contribute to ECM degradation of articular components in RA.

High serum and synovial fluid granulocyte colony stimulating factor (G-CSF) concentrations in patients with rheumatoid arthritis

OBJECTIVE

To determine the relationship between serum G-CSF, RA disease activity and the levels of inflammatory cytokines.

METHODS

Sixty-one patients (5 men and 56 women; mean age; 56.1 +/- 11.4 [+/- SD] years, range, 22-70 years) who were selected at random and met the American College of Rheumatology criteria for RA were examined. Granulocyte-colony stimulating factor (G-CSF) levels in sera and synovial fluid were measured by solid-phase radioimmunoassay (RIA). We also measured various indices of RA disease activity and serum levels of IL-1 beta, IL-6 and TNF-alpha by ELISA.

RESULTS

The morning stiffness, number of tender or swollen joints, ESR, Lansbury index and serum G-CSF levels in patients with active RA were significantly higher than the corresponding levels in patients with inactive RA. Serum G-CSF levels correlated significantly with morning stiffness, the number of tender or swollen joints and the Lansbury index. However, there was no correlation between serum G-CSF and ESR. High levels of IL-1 beta, IL-6 and TNF-alpha were detected in RA patients. The number of tender or swollen joints, ESR, Lansbury index, and IL-1 beta were significantly higher in G-CSF-positive RA patients than in G-CSF-negative RA patients.

CONCLUSION

Our results suggest that G-CSF produced by synovial cells stimulated by inflammatory cytokines might contribute to inflammatory arthritis in RA patients.

X-ray fluorescence analysis of trace metal ions following a preconcentration of metal-diethyldithiocarbamate complexes by homogeneous liquid-liquid extraction

A homogeneous liquid-liquid extraction method for 36 metal ions with diethyldithiocarbamate was studied. As a result, 11 metal ions were extracted as metal-chelates. Under the experimental conditions, the maximum concentration factor was 500 (i.e., 0.1 mL of sedimented liquid phase was produced from 50 mL of aqueous phase). Moreover, the proposed method was utilized as a preconcentration method for X-ray fluorescence analysis of these metals. The recovery of each metal was ca. 97-100%. All calibration curves were linear over the range of 5.0 x 10(-7) mol L-1 to 1.0 x 10(-5) mol L-1. The detection limits were at the 10(-8) mol L-1 levels and the relative standard deviations were below 5% (5 determinations). When the proposed method was used for the determination of contaminants in a synthetic sample (Al-based alloy model) and of components in an Au-Pd alloy, the results were satisfactory.

High serum concentrations of soluble E-selectin in patients with impaired glucose tolerance with hyperinsulinemia

High serum concentrations of soluble adhesion molecules are present in diabetics, but whether similar levels are present in patients with impaired glucose tolerance (IGT) is unclear. We measured serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), and sE-selectin in 128 nondiabetic Japanese subjects. The concentrations of sICAM-1, sVCAM-1, and sE-selectin in IGT patients (n=47) were not different from those in subjects with normal glucose tolerance (NGT; n=81). IGT patients were subdivided into two groups by the results of 75 g OGTT, those with low- (hypoinsulinemia; n=23) or high-insulin (hyperinsulinemia; n=24). The levels of sICAM-1 and sVCAM-1 were not different among NGT and IGT with high-insulin or with low-insulin. However, sE-selectin concentrations were significantly higher in IGT patients with high-insulin than in NGT and IGT with low-insulin (61.1+/-3.4, 47.1+/-1.8 and 43.7+/-3.9 ng/ml, respectively, P<0.001). Adjustment for age and gender did not influence the results. Serum sE-selectin concentrations correlated significantly with the area under the curve of insulin (AUC(insulin)), AUC(glucose), diastolic blood pressure, and triglyceride levels (r=0.35, 0.26, 0.18 and 0.21, respectively), and negatively with HDL-cholesterol levels (r=-0.20). Multiple regression analysis showed that AUC(insulin) was the only independent factor that correlated with sE-selectin levels (P<0.001). Our results indicate that hyperinsulinemia/insulin resistance may be responsible for the elevation of sE-selectin levels.

Increased insulin sensitivity and decreased insulin secretion in offspring of insulin-sensitive type 2 diabetic patients

To investigate the early defects of glucose metabolism in insulin-sensitive type 2 diabetes, we performed oral and frequently sampled intravenous glucose tolerance tests (OGTT and FSIGT) with minimal model analysis in 15 offspring of Japanese type 2 diabetics with normal insulin sensitivity (insulin resistance index of homeostasis model assessment [HOMA-R] < 2.0) and in 20 healthy control subjects without a family history of type 2 diabetes. The frequency of impaired glucose tolerance (IGT) was 40% (6 of 15) in the offspring and 0% (0 of 20) in the controls. Fasting plasma glucose (4.8 +/- 0.1 v4.6 +/- 0.1 mmol/L, P = .18) and immunoreactive insulin ([IRI] 29.9 +/- 2.5 v 28.3 +/- 2.5 pmol/L, P = .64) were comparable between the offspring and the controls. The rate of glucose disappearance (KG) was significantly lower in the offspring versus the control group (2.00 +/- 0.22 v 2.60 +/- 0.17 min(-1), P= .03). The insulin sensitivity index (Si) was significantly greater in the offspring versus the controls (2.68 +/- 0.41 v 1.71 +/- 0.17 x 10(-4) min(-1) x pmol/L , P = .02). First-phase insulin secretion (FPI) to intravenous glucose was significantly lower in the offspring versus the control group (886 +/- 110 v 2,296 +/- 267 min x pmol/L, P< .01). Glucose effectiveness (SG) was comparable between the offspring and control groups. The disposition index (Si x FPI) was significantly lower in the offspring versus the controls (2,106 +/- 256 v 3,652 +/- 490 x 10(-4), P = .02). When the offspring were subdivided into 2 groups by glucose tolerance status, both normal glucose tolerance (NGT) offspring and IGT offspring showed a significant decrease in FPI and increase in Si. Thus, although the offspring of insulin-sensitive type 2 diabetics had increased insulin sensitivity, the impairment in insulin secretion was more dominant. Our results suggest that the early metabolic abnormality in insulin-sensitive type 2 diabetes is an insulin secretory dysfunction despite increased insulin sensitivity.

Membranous lipodystrophy presenting with palilalia: a PET study of cerebral glucose metabolism

A case of membranous lipodystrophy (Nasu-Hakola disease; NHD) associated with palilalia was reported. A 38-year-old Japanese woman developed walking difficulty in her twenties. At age 35 she manifested neuropsychiatric symptoms characterized by euphoria, palilalia and dementia. A bone marrow biopsy showed periodic acid Schiff-positive membranous cystic lesions in the adipose tissue. Positron emission tomography with (18F)-2-fluoro-2-deoxy-D-glucose disclosed that regional cerebral glucose metabolism was decreased in the bilateral frontal white matter with mild hypometabolism in the thalamus and basal ganglia; all predominantly on the right. Taken together with the previous postmortem findings, it is postulated that frontal lobe hypofunction, predominantly in the right hemisphere, produced the unique neuropsychiatric symptoms in this patient.

Clinical effects of actarit in rheumatoid arthritis: improvement of early disease activity mediated by reduction of serum concentrations of nitric oxide

OBJECTIVE

We previously reported the presence of high serum concentrations of nitric oxide (NO) in patients with rheumatoid arthritis (RA). In this study we evaluated the effect of actarit on patients with early and advanced stages of RA and the relationship between RA activity and serum NO levels.

METHODS

Thirty-seven RA patients who were undergoing care at Sasebo Chuo Hospital were entered into the study. Patients were divided into two groups based on the severity of their disease: group I (stages I and II) and group II (stages III and IV). NO concentrations in serum samples were measured by the chemiluminescence method.

RESULTS

Morning stiffness, the number of tender and swollen joints, grip strength, pain score, modified Health Assessment Questionnaire score (mHAQ), ESR, CRP and the Lansbury index significantly improved during 24 weeks of treatment in group I. Patients in group II did not show improvement in morning stiffness, pain score, ESR or CRP during treatment. The concentrations of NO in group I were significantly reduced at 8 weeks after administration of actarit. Those in group II showed a delayed response; a significant decrease in NO occurred at 20 weeks. The improvement in the number of tender and swollen joints, grip strength, pain score, mHAQ and Lansbury index noted in group I preceded the fall in NO concentrations.

CONCLUSION

Our results demonstrate that actarit improves disease activity in early phase RA by suppressing serum NO levels. The results suggest that NO is a useful marker for monitoring improvement in the early stages of RA.

[A case of non-convulsive status epilepticus worsened Wernicke's aphasia reversely]

A 62-year-old right-handed woman had presented progressive speech impediment over 4 months. She was alert without any convulsions or involuntary movements. Neurological examination showed Wernicke's aphasia, constructional apraxia. Her magnetic resonance imaging (MRI) showed an old cerebral infarction in the left parieto-occipital area, in addition to ischemic changes in the bilateral deep white matter. Electroencephalography (EEG) revealed periodic lateralized epileptiform discharges (PLEDs) predominant in the posterior left hemisphere. The PLEDs as well as the cortical symptoms improved after an administration of anti-convulsive agents, thus establishing the diagnosis of non-convulsive status epilepticus (NSE). It should be emphasized that NSE manifesting as Wernicke's aphasia should be distinguished from dementia syndrome because it is a treatable disorder.

Induction of COX-2 expression by nitric oxide in rheumatoid synovial cells

Prostaglandins formed by cyclooxygenase (COX) enzymes are important mediators of inflammation. The contribution of inducible COX-2 in the rheumatoid synovium is well documented. In this study, we evaluated the contribution of nitric oxide (NO) to COX-2 expression in rheumatoid synovial cells. Exposure of rheumatoid synovial cells to a NO donor, SNAP, induced COX-2 protein expression in a dose-dependent manner. RT-PCR analysis also demonstrated that COX-2 mRNA was induced in SNAP-treated synovial cells. Dexamethasone at therapeutic concentrations markedly inhibited this NO-mediated COX-2 expression in synovial cells. In contrast to its effect on COX-2 expression, SNAP did not affect the constitutive expression of COX-1 in rheumatoid synovial cells. Our findings suggest that NO is an important modulator of COX-2 expression and that glucocorticoids exert their anti-inflammatory action in rheumatoid synovium, at least in part, by suppression of COX-2 induction.

Evaluation of filtration leucocytapheresis for use in the treatment of patients with rheumatoid arthritis

OBJECTIVES

To evaluate the efficacy of filtration leucocytapheresis (LCP) for rheumatoid arthritis (RA).

METHODS

LCP was carried out three times, with 1 week separating each session, in 25 drug-resistant RA patients.

RESULTS

During each session, 96, 98, 61, 84 and 8% of the granulocytes, monocytes, lymphocytes, platelets and erythrocytes, respectively, that entered the LCP filter were removed. The number of granulocytes, monocytes and lymphocytes in the peripheral blood significantly decreased during each session of LCP. However, there was no significant decrease in the number of circulating blood cells during the study period. On average, 110 x 10(8) granulocytes, 5.23 x 10(8) monocytes, and 20.5 x 10(8) lymphocytes were removed during LCP therapy. Assessment of RA before and after LCP showed a substantial and rapid improvement in the tender joints counts, swollen joint counts, and patient's and physician's assessments. No adverse reactions or complications were noted. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels decreased following LCP, although the change in the latter parameter was statistically insignificant. The concentrations of serum albumin, gamma-globulin, IgG, IgM, CH50 and rheumatoid factor titres did not change during or after LCP. Careful analysis indicated that 16 of 25 patients with RA showed > or =20% improvement following LCP therapy.

CONCLUSIONS

Our results suggest that filtration LCP to remove leucocytes from the peripheral blood exerts an immunomodulatory effect in patients with RA.

Does the production of nitric oxide contribute to the early improvement after a single low-density lipoprotein apheresis in patients with peripheral arterial obstructive disease?

Low-density lipoprotein (LDL) adsorption using a dextran sulfate cellulose (DSC) column is commonly performed for extracorporeal removal of LDL in hypercholesterolemic patients with peripheral arterial obstructive disease. We investigated whether the use of heparin or nafamostat mesilate as anticoagulants in a single LDL apheresis produced different clinical effects, or brought about the production of bradykinin and endogenous nitric oxide (NO) in these patients. LDL apheresis was performed in ten patients with peripheral arterial obstructive disease. We measured plasma levels of bradykinin, NO and nitrosylhemoglobin as well as skin temperature. Plasma levels of bradykinin increased 12-fold during LDL apheresis with heparin, but did not increase during LDL apheresis with nafamostat mesilate. LDL adsorption resulted in an immediate rise in skin temperatures (1-2 degrees C) of the lower ischemic legs irrespective of the type of anticoagulant used, and this persisted after the end of LDL apheresis for up to 60 min. There was a progressive and significant increase in plasma NO after the commencement of single LDL apheresis in both groups (heparin group: 64.0 +/- 17.3 micromol/l at baseline, 73.3 +/- 15.2 micromol/l 60 min after apheresis, P<0.005; nafamostat mesilate group: 65.0 +/- 18.8 micromol/l at baseline, 75.5 +/- 17.5 micromol/l 60 min after apheresis, P<0.001). On the other hand, levels of nitrosylhemoglobin increased significantly after 1000 ml of plasma treatment but the level decreased thereafter, although it was significantly higher than baseline 60 min after LDL apheresis. Our results suggest that a single LDL apheresis enhanced peripheral microcirculation, probably as a result of increased production of NO, irrespective of changes in bradykinin release.

Argatroban increases nitric oxide levels in patients with peripheral arterial obstructive disease: placebo-controlled study

Intravenous argatroban infusion therapy is widely used for the restoration of peripheral microcirculation in patients with peripheral arterial obstructive disease (PAOD). We investigated the effect of argatroban infusion therapy on plasma levels of nitric oxide (NO) and nitrosylhemoglobin (HbNO) in patients with PAOD compared with a placebo-treated PAOD group. The chemiluminescence method was used to determine plasma NO and HbNO. Argatroban was administered as a continuous intravenous infusion for 60 minutes and repeated daily over a period of 2 weeks in 10 patients with PAOD. Treatment significantly improved the clinical signs and symptoms. Serial thermograms showed a 1-2 degrees C rise in the temperature of the affected legs in all patients immediately after intravenous argatroban infusion therapy. Enhancement of the peripheral circulation was maintained after the end of argatroban infusion for up to 90 minutes despite elimination of argatroban from the circulation. Furthermore, there was a progressive and significant increase in the mean concentration of plasma NO in PAOD patients after commencement of argatroban infusion (baseline, 58.0 +/- 13. 7;90 minutes after infusion, 65.7 +/- 13.4 microM; P < 0.01). HbNO significantly increased from a baseline value of 1063 +/- 126 to 1460 +/- 250 nM at 30 minutes after infusion (P < 0.01). However, the level of HbNo decreased thereafter, although it remained significantly elevated, even at 90 minutes after the end of argatroban infusion. Our results suggest that argatroban may lead to increased HbNO and plasma NO, and this may contribute to the improved microcirculation in PAOD patients.